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# paramagnetic species co

29/12/2020 23h39 • atualizado 29/12/2020 23h39

Hence, KO2 behaves as paramagnetic molecule. The atomic radiusis: Find out the solubility of $Ni(OH)_2$ in 0.1 M NaOH. Which of the following conversions involves change in both shape and hybridisation ? Bond length decreases. Diamagnetism occurs when orbital electron motion forms tiny current loops, which produce magnetic fields. If the the bond order is fractional, species are paramagnetic. 14) Which complex of nickel is paramagnetic in nature- (a) K 2 [NiCl 4] (b) K 2 [Ni(CN) 4] (c) K 2 [Ni(CO) 4] (d) [Ni(NH 3) 4]Cl 2. Often definitive identification of the individual species is realized solely from the analysis of the EPR spectrum. QED dictates that the magnetic moment of an electron arises from its â¦ Superparamagnets are materials that show a net paramagnetic response, yet display ferromagnetic or ferrimagnetic ordering at the microscopic level. Find the diameter of the venturimeter at the throat, if the coefficient of discharge is 0.96 solvedâ. I.E. ozone layer. The difference of pressures at entrance and throat read by a mercury manomete CN-, CO and NO+ are isoelectronic with 14 electrons each and there is no unpaired electrons in the MO configuration of these species. The resonant transfer of the NV centersâ polarized electronic spins to the electronic spins of these species generates conspicuous features in the NV photoluminescence by employing magnetic eld scans along the [100] crystal â¦ Suslick Paramagnetic 1H NMR: Relaxation Time Question: Give The Complete Electron Configuration Of Cobalt, Co, And The Complete Or Abbreviated Electron Configuration Of Co2+ And Co3+. 1 Î¸ 1 and Î¸ 2 represent the dihedral angles between the 2p z orbital at C 1 and the planes containing the C 1-C Î²-H Î²1 bonds and the C 1-C Î²-H Î²2 bonds, respectively.. 2 Y d is one of the two tyrosyl radicals in PSII.. AIPMT 1995: Which of the following species is paramagnetic ? About 20 km above the earth, there is an Single crystals of sodium nitrite were irradiated with Co 60 gamma rays at 77°K and studied by the paramagnetic resonance method. In contrast with this behavior, diamagnetic materials are repelled by magnetic fields and form induced magnetic fields in the â¦ 1.10 x 10^2. Question: How Many Of The Following Species Are Paramagnetic? What is the hybridization and geometry of the compound $XeOF_4$ ? Structure anions of acids, $HNO_{3}, H_{3}PO_{4}$ and $H_{2}SO_{4}$ are, respectively. Paramagnetic materials are attracted strongly to a magnetic field. Al-13 All Are Paramagnetic 2 1 4 3 Which Set Of Quantum Numbers Is Correct And Consistent With N - 4? So these are diamagnetic. O-2 is paramagnetic due to the presence of one unpaired electron. Question: Is al3 a Paramagnetic or Diamagnetic ? EPR can often detect the interaction between radical and other paramagnetic species. Sc3+ Clâ Ba2+ Se. Which of the following is a redox reaction ? Identify compound X in the following sequence of reactions: Identify a molecule which does not exist. An anisotropic three-line hyperfine spectrum associated with a single paramagnetic species was observed. 15) Determine the number of unpaired electrons for [NiCl 4] 2-, known to be paramagnetic. In this video I shared trick to find Paramagnetic and Diamagnetic species. Find The Number Of Unpaired Electrons In Each. Since there is an unpaired electron, $$Cl$$ atoms are paramagnetic (but weakly since only one electron is unpaired). If the species is paramagnetic, the mass reading of the balance will increase when the field is switched on.Classify these species as paramagnetic or diamagneticNO F2 O2 COWhich species will have the strongest mass shift on a magnetic susceptibility balance?a) F2b) O2c) NOd) CO How many of the following species are paramagnetic? Please log inor registerto add a comment. An atom is considered paramagnetic if even one orbital has a net spin. We know that a molecule becomes paramagnetic due to the presence of unpaired electrons. Sr Ð¡Ð¾ Ar AI The Atomic Numbers For The Atoms Above Are As Follows: Fe-26, Sr=38, Co-27. 1. Which of the following species is paramagnetic ? Paramagnetic Species are those atoms, ions or radicals which have unpaired electrons. Among the following, the paramagnetic compound is a. Na2O2 b. O3 c. N2O d. KO2Sol. â¦, r is 5 cm, when water is flowing at a rate of 50 lit/sec. O_2^- in KO2 has 17 electrons, species â¦ Find The Paramagnetic Species Among Them. Hello dear here is your answer â¥ â¥ â¥ï¸â¥ï¸, lactobacilli are used for making yoghurt from milkâ, block of mass 2 kg moving at a speed of 20 metre per second accelerates at 2 metre per second for 5 seconds find its final kinetic energyâ, Bohot logo ke liye abhi good morning but kya kare mera bhi good night nhi hua â, Good morning brainly jantaKya kare neend nhi aa rahi h and mere earphones ka RIP ho gaya aaj subah to koi with earphones wale ideas nhi â, 11 What is the opposite character of violet colour pea flowera) Green(b) yellow (c) White (d) Curlyâ, Zindegi meri h kisike baap ke khardid nhi rhi h â, hey guys good nightgive thanks get thank sâ, is any girl online to chat with me ....â, A Venturimeter is installed in a horizontal pipe line of 30 cm diameter. Answer: al3 is a Paramagnetic What is Paramagnetic and Diamagnetic ? Correct answers: 1 question: When the paramagnetic [co(cn)6] 4â ion is oxidized to [co(cn)6] 3â , the ion becomes diamagnetic. The oxidation number of chromium in potassium dichromate is, The oxide, which cannot act as a reducing agent, is. A) There Are 3 Unpaired Electrons In â¦ Separate species .tbd.molecules, ions, radicals, having a high paramagnetic contrast, e.g., one highly paramagnetic species. Fe3. All materials are diamagnetic. According to molecular orbital theory, which of the following will not be a viable molecule ? Which Of The Following Is Correct? true? Reaction between acetone and methyl magnesium chloride followed by hydrolysis will give : Identify the correct statements from the following: Which of the following set of molecules will have zero dipole moment ? solution, we get. In cases where two or more paramagnetic species co-exist, the spectral EPR lines arising from each can be simultaneously observed. (A) CO2 (B) NO (C) O2-2 (D) CN-. Diamagnetic atoms repel magnetic fields. A diamagnetic species has no unpaired electrons, while a paramagnetic species has one or more unpaired â¦ Ar=18. Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. 16) Amongst the following, no. Classification of Elements and Periodicity in Properties. A paramagnetic electron is an unpaired electron. The hyperfine structure arises from a nitrogen nucleus in the paramagnetic species at â¦ Diamagnetic substances are weakly repelled by a magnetic field. no. An atom could have ten diamagnetic electrons, but as long as it also has one paramagnetic electron, it is still considered a paramagnetic atom. Ferrofluids are an â¦ Given the species : N2, CO, CN^- and NO^+ . Calculate the total energy (in kJ) contained in 1.0 mol of photons, all with a frequency of 2.75 x 10^8 MHz? in any species if no of unpaired electrons remain in the orbitals of any subshell then it is known as paramagnetic species and if no unpaired electrons remain in the orbitals of any subshell then it is known as diamagnetic species. Click here to buy a book, photographic periodic table poster, card deck, or 3D print based on the images you see here! On electrolysis of dil.sulphuric acid using Platinum (Pt) electrode, the product obtained at anode will be: An element has a body centered cubic (bcc) structure with a cell edge of 288 pm. More specifically, it refers to whether or not a chemical species has any unpaired electrons or not. Which of the following protein destroy the antigen when it enters in body cell? Check Answer and Solution for above question from Chemis Suslick Paramagnetic 1H NMR © 2012, K.S. however, when the paramagnetic [co(ox)3] 4â is oxidized to [co(ox)3] 3â , the ion remains paramagnetic. 3 © 2012, K.S. Here $B$ is bond pair and $L$ is lone pair. Basically, paramagnetic and diamagnetic refer to the way a chemical species interacts with a magnetic field. species like B2 are paramagnetic due to presence of two unpaired electrons in pi 2p bonding molecular orbitals according to molecular orbital theory. Paramagnetic NMR spectroscopy 6 is central to many fields from chemical and structural biology for studying the structure, dynamics and interactions of proteins 1b, 1c, 7 to probing spinâstate populations in spinâcrossover compounds 8 and the structural characterisation of paramagnetic complexes 9 and â¦ How Diamagnetism Works . So, F- is also diamagnetic because all its electrons are paired up. So, in KO2 the oxygen atoms bear -1/2 oxidation state and they also behave as a free radical species, having an unpaired electron. Choose the paramagnetic species from below. Step 4: Determine whether the substance is paramagnetic or diamagnetic. s, â¦ Paramagnetic Paramagnetism is a form of magnetism whereby certain materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. This site is using cookies under cookie policy. You can specify conditions of storing and accessing cookies in your browser. Paramagnetism is the result of an unpaired electron having a magnetic dipole moment. explain these observations in detail using â¦ Which one of the following Paramagnetic Paramagnetism is a form of magnetism whereby certain materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the â¦ Exercise $$\PageIndex{1}$$ Indicate whether boron atoms are paramagnetic or diamagnetic. Titanium and aluminum are metallic elements that are paramagnetic. Ca. Uncertainty in position of an electron (mass of an electron is =$9.1\times10^{-28}g)$ moving with a velocity of $3 \times 10 ^4$ cm/s accurate upto 0.001% will be (use $\frac{h}{4\pi}$ in uncertainty expression where $h = 6.626 \times 10^{-27}$ erg s), The radius of hydrogen atom in the ground state is 0.53 $\mathring{A}.$ The radius of $Li^{2+}$ ion (at. Paramagnetic nuclear magnetic resonance spectroscopy refers to nuclear magnetic resonance (NMR) spectroscopy of paramagnetic compounds. = 3) in a similar state is, By passing $H_2S$ gas in acidified $KMnO_4$ In paramagnetic materials, the magnetic moments of the electrons don't completely cancel each other out. The more paramagnetic the species is, the largest the mass shift-O2. optical detection of paramagnetic species, such as hydrogen-related complexes, in a CVD-grown diamond. So, Mg+2 is also diamagnetic because all its electrons are paired up. In the molecular orbital diagram for the molecular ion, $\ce{N_2{^{+}}}$, the number of electrons in the $\sigma_{2p}$ molecular orbital is : In Wolff‐Kishner reduction, the carbonyl group of aldehydes and ketones is converted into. EXAMPLE 3 In another experiment the relative permeation of O 2 against N 2 was measured through a relatively thick 9-mm YBa 2 Cu 3 O 7 -Î´ pellet and through a YBa 2 Cu 3 O 6 -rich sample of the â¦ here âox' denotes a bidentate chelating ligand. Paramagnetism is a form of magnetism which occurs only in the presence of an externally applied magnetic field. Keturakis, in Comprehensive Inorganic Chemistry II (Second Edition), 2013. When an external magnetic field is applied, â¦ So, Na+ is diamagnetic because all its electrons are paired up. Given that the ionic product of $Ni(OH)_2$ is $2 \times 10^{-15}$. Atomic orbitals. Hope it will help u plzzzzz mark as the brainliest mitgliedd1 and 16 more users found this â¦ These materials adhere to the Curie law, yet have very large Curie constants. If the bond order is integer, species is diamagnetic ( except 10 electron, 16 electron species). statements about ozone and ozone layer is New salts of fullerene C60â¢â radical anions with N,N,Nâ-trimethylpiperazinium cations (TMP+) containing neutral cobalt(II) porphyrin molecules: {(TMP+â¦ as bond order increases. of species with tetrahedral geometry is : [Pd(CN) 4] 2â, [Ni(CN) 4] â¦ 7.06.2.6 Electron Paramagnetic (or Spin) Resonance Spectroscopy. Although most NMR measurements are conducted on diamagnetic compounds, paramagnetic samples are also amenable to analysis and give rise to special effects indicated by a wide â¦ Which of the following statements are true for these (A) All species are paramagnetic asked Oct 10, 2019 in Chemical bonding and molecular structure by KumarManish ( 57.6k points) The interaction between radical and other paramagnetic species. These species can only be compared while in the gaseous state, not in a compound. In hydrogen azide (above) the bond orders of bonds (I) and (II) are : The most polar compound among the following is : Identify the pair in which the geometry of the species is T-shape and squarepyramidal, respectively : The incorrect geometry is represented by : What will be the geometry of the compound $MB_4L_2$ ? In any species if no of unpaired electrons remain in the orbitals of any subshell then it is known as paramagnetic species and if no unpaired electrons remain in the orbitals of any subshell then it is known as diamagnetic species. Identify the number of valence electrons in Cl^-1. 8. Which species will have the strongest mass shift on a magnetic susceptibility balance?-O2-F2-CO-NO. Wachs, C.J. Paramagnetic materials are attracted to magnetic fields, hence have a relative magnetic permeability greater than one (or, equivalently, a positive magnetic susceptibility).The force of attraction generated by the applied â¦ ( \PageIndex { 1 } \ ) Indicate whether boron atoms are paramagnetic the strongest mass shift a. Of storing and accessing cookies in your browser single paramagnetic species are atoms... The oxide, which of the electrons do n't completely cancel each other out when... Shift on a magnetic field is applied, â¦ in cases where two or more paramagnetic.... 17 electrons, species is paramagnetic and diamagnetic to whether or not a similar state is, the magnetic of. Diamagnetic substances are weakly repelled by a magnetic field agent, is a net response. Storing and accessing cookies in your browser will have the strongest mass shift on a magnetic dipole.. Is also diamagnetic because all its electrons are paired up the microscopic level it enters in cell... 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blueollie

Saving a bust of a workout

Well, our “fake spring” is over. Back to winter time, though the snow isn’t that bad for this time of year. But any is too much for me. :-)

So I took it indoors. 2 mile treadmill in 21:20, then I thought about trying 4 miles on the track. I was laboring in mile 2 and so I changed my mind and made it 5K (lane 2)
8:57, 8:46, 8:35 (26:19), 27:19. then I walked on the treadmill, starting at 3.9 mph and increasing every 2 minutes then playing between 12:15 and 11:45 mpm (mostly 12 mpm): 38:45 for 3, 40:02 for 3.11 (5K)

That was enough for today; it was far from stellar but …well, not that bad for 1 month after blood donation and for this not being a race.

Now to attempt to be productive.

New Hampshire: Trump: big favorite. Sanders: HUGE favorite.

These are the odds. $\frac{1}{41}$ odds for Sanders in New Hampshire!

From Sam Wang:

On the Democratic side, Bernie Sanders is at a median of 55%, and Hillary Clinton is at 43%. For both of them, the one-sigma uncertainty is 2 percentage points. An upset victory by Clinton looks highly unlikely…but if she held Sanders to a single-digit margin of victory, that would be considered a strong showing in a state that is almost as white as Sanders’s neighboring state of Vermont.

Note: a local Sanders supporters group is having a debate watch party at a sports bar that is near a commitment that I have just prior. So I’ll probably go to that. I’ll be nice and keep my mouth shut and mostly just listen.

What I really want to do is to find a Republican watch group for a Republican debate so I can see how they view things.

February 9, 2016

I am dying.

February 9, 2016

Running on empty (not a bad thing)

I’ve been tired lately, but not really run down. My sleep has been, well, too short. But I wake up..and can’t go back to sleep. I probably need to ignore the internet late in the evening.

So, I slept in a bit and skipped weights and only swam: (weight: 186 prior to swimming; I feared I would be “Moby Dick” after this weekend’s indiscretions)
500 free, 500 drill/free with fins, 5 x (100 pull, 100 free), 4 x 50 fly/back with fins.

Ok, I know that I have to stay with lifting so I squeezed in a mini lifting workout over lunch. The gym wasn’t as crowded as I feared it would be:

rotator cuff
pull ups (strong) 15-15-10-10
incline bench press: 10 x 135, 9 x 150 (wanted 10, dammit!) 10 x 135
military: 2 sets of 10 x 40 standing, 10 x 200 machine (100 each arm)
rows: 3 sets of 10 x 110 machine
abs: twist crunches (2 sets of 12), yoga leg lifts (2 sets of 10), moving bridge, headstand (adding to the “eccentric professor” lore)

TMI: I’ve got something like a cold sore in my throat (tonsils) and have had it for a few days. I am recording this to see how it feels in a week or so. I don’t think that I am ill because workouts have been fine; about normal for me.

February 8, 2016

On the Sanders vs. Clinton debate…

I’ve been following this “Sanders vs. Clinton” debate both online and with various friends. Though I have some Clinton supporters as friends, I haven’t really seen the attacks her supporters have made on Sanders supporters. So I won’t comment on them.

I have heard and read what some of the Sanders people say, and they say some interesting things. For one, they are prone to cherry picking the polls that tell them what they want to hear.

I suppose that is a very human thing to do; we do that in, say, relationships all the time. Oh yes, fans of given sports team do that too. :-)

Here Paul Krugman talks about the “electablility” issue. I understand why that is a valid concern.

But it isn’t for me. IF I knew that the Democrat nominee would win the election (and I strongly thought that in 2008) I would still vote for Hillary Clinton this time. Reason: I give a lot of credit for being smart, well rounded, knowledgeable and having political skill. I think that she is more realistic about how our country is. No, even if Sanders wins the Presidency, Mitch McConnell isn’t going to see a massive protest outside of his office (Sanders said something to this effect at a debate; he says that this must happen for the country to get behind his proposals).

But what happens even more, in my experience, is an intellectual sin whose effects can be just as bad: self-indulgence. By this I mean believing things, and advocating for policies, because you like the story rather than because you have any good evidence that it’s true. I’ve spent a lot of time over the years going after this sort of thing on the right, where things like the claim that Barney Frank somehow caused the financial crisis so often prevail in the teeth of overwhelming evidence. But it can happen on the left, too — which is why, for example, I’m still very cautious about claims that inequality is bad for growth.

On electability, by all means consider the evidence and reach your own conclusions. But do consider the evidence — don’t decide what you want to believe and then make up justifications. The stakes are too high for that, and history will not forgive you.

I say this for the benefit of the neutral reader. Of course, the “true believers” will just say that I am either a sellout or someone who has been bamboozled or duped; that somehow I just don’t have their insight, powers of perception, or am, well, less principled? I have to laugh.

I’ll make this clear: if Sen. Sanders wins the primary, I’ll vote for him and open up my (meager) checkbook for him. I like the man and respect him. And there are many Sanders supporters that I like (even love?) and respect. But this time around, I honestly believe that Hillary Clinton is the better choice.

February 8, 2016

Playing too much?

Well, today wasn’t very productive but I enjoyed it.
Morning:

I was a bit sloppy and I wasn’t very fast. It took me 3:19 to cover this course; it was probably (realistically) about 13 miles (walking). I saw several runners; course was to Bass Pro, back, then to the end of Springdale (via the goose loop), mausoleum loop, back via the gooseloop with 2 extra gooseloop laps.

Then came a Bradley womens’s game; BU lost to Southern Illinois 65-51; SIU had a player from East Peoria who drew many local supporters. They simply shot the ball very well and got open looks.

Tracy met me there for most of the game; walked back to the house with me and we had our own “Super Bowl” party with some Middle Eastern food from Jerusalem Restaurant (highly recommended).

The Super Bowl itself was a defensive slugfest which the Broncos won 24-10; the first Bronco TD came on a strip sack/fumble recovery and the second was set up by a forced fumble inside the 10. A long punt return set up one field goal. The Panthers had a drive for a touchdown; their field goal game via a turnover.

Hopefully I’ll play a little LESS this upcoming week and have something more worthy of being written about. :-)

February 8, 2016

Primary Races: Super Bowl Edition

Off to walk in a bit. During the winter, when I have the time, I like to wait for the sun to come up so I can get some sunshine.

I missed last night’s Republican debate. Now as far as those “Rubio is the Republican Obama”: evidently he didn’t wear the “front runner” mantel very well. I guess that repeating rehearsed soundbites only goes so far.

Democratic Race Yes, Senator Sanders is a heavy favorite in New Hampshire and deserves to be. But nationally, some Sanders supporters have focused on ONE national poll that was good for them. Two other national polls taken at the same time show, well…something very different and something more in line with previous polling.

I find it ironic that some Sanders supporters are making exactly the same mistake that Romney supporters made in 2012: cherry picking the outlier poll that tells you what you want to hear and ignoring the numerous other polls that don’t give you the result that you want. Sam Wang talks about this and other topics here.

General Election
If the 2016 election is going to be a referendum on President Obama, well, his approval ratings are, well, average compared to previous presents, and downright stellar compared with the previous president. Note: the dotted line is the historical trend, and the light green line is President Obama’s, and the dark green is President W. Bush’s.

February 7, 2016

Meanwhile the spouse (personal)

Lynn: here are some of Barbara’s vacation photos (so far); I’ve selected a few from each set. She is El Salvador.

February 7, 2016 Posted by | photos | | 1 Comment

Very fun day….

Well, the weekend started on Friday when the Bradley women beat Evansville by 12. That was a great start.

So this morning I start out for a 15 mile run. It was 27 F at the start but it did warm up a bit; it took me 2:56 to do and I had to work through some rough patches at mile 12 or so.

Course: to Bass Pro, back to the trail and then to the “almost 3 mile mark; the little driveway before the angled road crossing and back.

Of interest:

1. While running over the Bob Michael Bridge (ON the sidewalk) I heard one honk. Then I saw a SUV honk a couple of times…and then someone evidently flipped me off (or flipping off another driver? It sure looked like it was aimed at me…) Hmmm.

2. On the trail toward East Peoria a “30-40 year old” woman passed me..not that fast. Perhaps she was doing 10 minute miles or thereabouts? She walked, I caught her, she caught me again and she stopped at Main Street in East Peoria. I kept going.

3. On the way back I had a rough patch or two where I wanted to mentally quit. I didn’t and it was ok.

Later, I shared Indian Buffet with a dear friend. We probably spent 1:30-1:45 there or so, just talking about many things. It was great food and great company.
We both had some professional work to do so both of us went to our respective offices.

I took some photos for “proof” (and to play along with a Facebook “back and forth” ). And Lynn, if you are reading this, yes, it is really that bad, most of the time. :-)

I did get one task done (need to do one more).

Then it was to watch the Bradley men play.

Warm ups.

They raced out to a 33-23 lead at the half and left to a standing ovation. Indiana State came back to cut it to a 3 point lead. Bradley got it back to 9, but ISU came back again and it was all even with 3:3x left in the game. But BU played with poise, got some stops and hit some big free throws. It was a 4 point lead with 3x seconds to go, then only a 1, but BU held on and ended up winning 63-58.

Now the women go for the weekend sweep tomorrow (before the Super Bowl) and I’ll be there, this time with a friend.

So, I saw none of the Republican debate. Others did, and evidently it didn’t go that well for Marco Rubio. I’ll watch clips in the morning.

February 7, 2016

Making the swim fun…

Ok, I stayed up too late watching Hillary Clinton and Bernie Sanders debate. I loved the debate; real differences were discusses and there were differences in both vision, approach and policy. Here was a good Fact Check: both candidates did ok. There were no egregious lies.

But I felt tired and run down prior to getting to the gym.

weights: rotator cuff
pull ups: 5 sets of 10 (decent sets)
bench press: 10 x 135, 5 x 185 (risky), 9 x 170 (wanted 10, but the gym was empty and didn’t want to risk getting stuck, even with our bench having safety catches)
incline press: 10 x 140
military (dumbbells): 2 sets of 12 x 50 seated, supported, 1 set of 10 x 40
rows: 3 sets of 10 x 50 (dumbbell, each arm)
abs: 2 sets of 12 twist crunches, 2 sets of 10 yoga leg lifts, head stand (got into it right away, but a little unsteady)

swim: 1000 easy, 5 x 100 drill/swim (fins), 5 x 100 (alt pull/swim), 2 x 100 IM

During the 1000, I noticed that Jason was gaining on me. Yeah, he is 15 years younger and runs a 3:12 marathon and 23:xx for 4 miles. So he has a better “aerobic engine” than I have. I was faster in the water last year, but as his form improved, the predictable happened.

Well, dammit…I wasn’t going to let him catch me today and when I touched the wall just a few seconds before he could catch me, I did a fist pump! :-)

February 5, 2016

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# Why does the short rate in the Hull White model follow a normal distribution?

Consider Hull White model $dr(t)=[\theta(t)-\alpha(t)r(t)]dt+\sigma(t)dW(t)$ when we solve the SDE above we have $r(t)=e^{-\alpha t}r(0)+\frac{\theta}{\alpha}(1-e^{-\alpha t})+\sigma e^{-\alpha t}\int_{0}^{t}e^{\alpha u}dW(u)$ and when we take expectation and variance we have $r(t) \sim N(e^{-\alpha t}r(0)+\frac{\theta}{\alpha}(1-e^{-\alpha t}),\frac{\sigma^2}{2\alpha}(1-e^{-\alpha t}))$.

I know the calculate how find SDE and find expectation or variance but I don't understand why $r(t)$ has normal distribution.

thanks.

For simplicity, we assume that $$\alpha$$ is a positive constant. You need to show that, for any $$t>0$$, \begin{align*} M_t = \int_0^t e^{\alpha u} dW_u \end{align*} is normally distributed, where $$\{W_t, \, t \ge 0\}$$ is a standard Brownian motion with respect to the filtration $$\{\mathscr{F}_t,\, t \ge 0\}$$. Here, we employ the time-changed Brownian motion technique. For $$t\ge 0$$, let $$\mathscr{G}_t = \mathscr{F}_{\frac{1}{2}\ln(1+2t)}$$. Consider the process $$X=\{X_t, t \geq 0\}$$, where \begin{align*} X_t = \int_0^{\frac{1}{2}\ln(1+2t)} e^{\alpha u} dW_u. \end{align*} Then $$X$$ is a continuous martingale with respect to the filtration $$\{\mathscr{G}_t,\, t \ge 0\}$$. Moreover, \begin{align*} \langle X, X\rangle_t &= \langle M, M\rangle_{\frac{1}{2}\ln(1+2t)}\\ &=\int_0^{\frac{1}{2}\ln(1+2t)} e^{2u} du =t. \end{align*} By Levy's martingale characterization of Brownian motion, $$\{X_t, t \ge 0\}$$ is a Brownian motion. That is, for $$t >0$$, $$X_t$$ is normally distributed. Consequently, for any $$t >0$$, \begin{align*} M_t &= \int_0^t e^{\alpha u} dW_u\\ &=X_{\frac{1}{2}(e^{2t}-1 )} \end{align*} is normally distributed, and $$r_t$$ is also normally distributed.
• $X_t$ is the product of a function of $t$ and an Ito integral wich is a martingale. How you say that $X_t$ is a martingale too? – ab94 Sep 5 '19 at 17:48
This is a special case of the question of why $$\int_0^T f(t) dW_t$$ is normally distributed for a continuous function $f(t).$ This Ito integral can be approximated by a sum $$\sum_{i=0}^{N-1} f(i T/N) (W_{(i+1)T/N} - W_{i T/N}) .$$ The Brownian increments $(W_{(i+1)T/N} - W_{i T/N})$ are independent normally distributed random variables. The key point is that the sum of independent normally distributed variables is again normally distributed.
• The sum, which is normal, converges to the ito integral in $L^2(P)$, and the key point is that the $L^2$ limit of a sequence of normal random variables is still normal. – Gordon May 18 '15 at 22:36


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# Estimating the probability of something that never happened

### pmercatoris

#### 21/11/2018

Have you ever needed to estimate the probability of a rare event? So rare that you haven’t been able to encounter it in real data? Well, what if I told you that there exists a way to calculate a statistically correct approximation. Oh, and you won’t even need a calculator!

Recently I have just heard of the statistical “Rule of three”. No, this is not the mathematical “Rule of three” where if:

then:

Nor is it the rule where, in literature, a trio of events is always more humorous/satisfying than any other number. And neither is it the “Rule of thirds” helping the photographic composition.

No, this one states that it is possible to estimate the probability of an event that has never occurred, to actually happen. For example, imagine you are looking for the probability of a typo to occur in a book. You would ideally count all the typos in the book and divide by the number of pages. However, what if you can only read the first 30 pages, and you need to give an estimate. Unfortunately, you haven’t found any typo in those pages. Would you then estimate that probability to be 0? There must certainly be a typo. There has to be!

Following an easy and useful rule of thumb, you can give a statistically correct estimate with a 95% confidence. And this is just by dividing 3 by n (the number of observations with counted and the event hasn’t occurred). So in our previous example, having counted 30 pages we can estimate with a 95% confidence that the real proportion is between 0 and 3/30. As most statistical inference rules though, it is recommended to have n  30 (See Wikipedia for more details).

However, I wanted to know whether this method could be applied to finance. More particularly, to estimate the probability of a big loss in a series. To do this, I have counted a number of drawdown events lower than -5, -10 and -15% for the S&P 500 Index since the 1st of January 1965. Then, for each month I have calculated the proportion of such event over the passing months, without using the “Rule of three”. As we can see, if we were to use that proportion as the probability of such event to occur in the future, we would greatly underestimate the risk, as the probability would be 0 for more than one year (for a drawdown bigger than -15%). That isn’t very reassuring when all we want is controlling the risk…

Applying the “Rule of three”, we get a rapidly decreasing (initially) followed by a probability that never reaches 0. In the graph below, we can actually see what was the probability estimated by the rule before the first event was registered. We can then see how the real probability stays below that prediction.

Another way I wanted to test it, was to use generated (but realistic) financial time series. Below, we can see 20 of the 1000 series generated over the same period (from January 1965).

The simple test used was to calculate the proportion of the 1000 time series where the “Rule of three” estimate was higher than the real proportion of events over the whole series. This was done of varying events severity (0 to – 15% loss in a month).

As we can see, the proportion does not quite reach 95%, but that might be because 1000 series aren’t enough series to estimate the real distribution, as I was accepting any estimate from the “Rule of three” with n 30 (very close to the minimum required). Then the proportion drops from -8% loss, but that is most likely due to the fact that the frequency of events is just too high.

Overall, I could not really reject the validity of the “Rule of three”, but I have certainly managed to show that it is only an estimate. It is better to use it than not when estimating future probabilities of events that did not happen, but this only gives a 95% confidence. There is still a 5% chance to be wrong…

Let me know in the comments, if you have managed to use that rule in any other meaningful way!


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# Gear Ratio RPM Calculator

Created by Vishnuvardhan Shakthibala
Reviewed by Rijk de Wet
Last updated: Apr 05, 2022

Are you wondering how to find the rpm of your gear system? Don't fret! Our gear ratio rpm calculator will help you do that in a flash!

• The relation between the gear ratio and the gear speed in rpm; and
• How to use our gear ratio rpm calculator.

## What is a gear ratio?

Gears are ubiquitous mechanisms, and you can find them in watches, bicycles, cars, etc. The gear ratio is an important parameter that describes the characteristics of a gear system.

The gear ratio is the ratio of the number of teeth of the driver gear to the number of teeth of the driven gear.

Now that we know what does gear ratio mean, the relationship between gear ratio and gear rpm is given as:

$\footnotesize \text{Output gear rpm} = \frac{ \text{Input gear rpm} }{ \text{Gear ratio} }$

Using the above relation, we can calculate the gear rpm by using the gear ratio.

## What is the difference between gear rpm and gear speed?

The gear rpm and gear speed are the quantities used to represent how fast an object rotates.

• Gear speed indicates how much angle is spanned by a rotating object per second. To convert from gear rpm to gear speed in $\text{rad}/\text{s}$: multiply gear rpm by $\pi/30$.
• Gear rpm indicates how many rotations a rotating object makes per minute. To convert from gear speed in $\text{rad}/\text{s}$ to gear speed in rpm: multiply gear speed in $\text{rad}/\text{s}$ by $30/\pi$.

## How to use our gear ratio rpm calculator?

To use our calculator, use the following guidelines:

• First, you must know about the number of teeth present in your gear system. The gear system includes the input (driver) and output (driven) gear. Input gear is the gear that drives the output gear.
• Insert the number of teeth for input and output gear in Input gear teeth and Output gear teeth fields.
• Right after you insert the teeth information, you will obtain the Gear ratio.
• Now insert the rpm of your input gear to obtain the output gear rpm.

Great! Now you know how to use our calculator to find output gear rpm quickly.

Do you have any other problems related to gears that you want solve? If yes, then check out our other gear-related calculators:

## FAQ

### What is the gear speed of 30 rpm in rad/s?

The gear speed in rad/s is π. To obtain gear speed in rad/s from rpm: multiply the gear speed in rpm by and divide by 60.

### How to calculate the output torque from gear ratio?

To calculate the output torque from gear ratio, use the following guidelines:

• Obtain the information about the number of teeth present in the input and the output gears;
• Take the ratio of the number of teeth of the input gear to the number of teeth of output gear to find the gear ratio; and
• Find output torque by multiplying the input torque by the gear ratio.
• Awesome, now you know how to find the output torque given you know the gear ratio and input torque of the gear system.

### How do I find the gear speed in rpm given its speed in rad/s ?

To calculate the gear speed in rpm, use the following steps:

• Multiply the gear speed in rad/s by 60;
• Now divide the obtained quantity from step 1 by to obtain the gear speed in revolution per minute (rpm); and
• Cool!, Now you can easily convert the gear speed in rpm to rad/s.
Vishnuvardhan Shakthibala
Input gear teeth number
Output gear teeth number
Gear ratio
:1
Input rotational speed
rpm
Output rotational speed
rpm
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Article | Open

# Joint Analysis of Radiative and Non-Radiative Electronic Relaxation Upon X-ray Irradiation of Transition Metal Aqueous Solutions

• Scientific Reports 6, Article number: 24659 (2016)
• doi:10.1038/srep24659
Accepted:
Published online:

## Abstract

L-edge soft X-ray spectroscopy has been proven to be a powerful tool to unravel the peculiarities of electronic structure of transition metal compounds in solution. However, the X-ray absorption spectrum is often probed in the total or partial fluorescence yield modes, what leads to inherent distortions with respect to the true transmission spectrum. In the present work, we combine photon- and electron-yield experimental techniques with multi-reference first principles calculations. Exemplified for the prototypical FeCl2 aqueous solution we demonstrate that the partial yield arising from the Fe3s → 2p relaxation is a more reliable probe of the absorption spectrum than the Fe3d → 2p one. For the bonding-relevant 3d → 2p channel we further provide the basis for the joint analysis of resonant photoelectron and inelastic X-ray scattering spectra. Establishing the common energy reference allows to assign both spectra using the complementary information provided through electron-out and photon-out events.

## Introduction

X-ray spectroscopic methods are indispensable for probing the structure of matter. The recent developments in the vacuum liquid-microjet technique have broadened the applicability of especially soft X-ray spectroscopy to highly volatile liquid solutions1,2. The microjet in conjunction with X-rays provides in situ access to the electronic structure of atomic and molecular solutes. Hence, solute–solvent interactions as well as short-lived chemically reactive intermediates produced upon X-ray excitation or ionization can be studied in great detail1,2,3,4. Among the prominent applications is the investigation of aqueous transition-metal (TM) ions, in particular iron-water complexes, which play a key role in biological and physical-chemical processes5,6,7,8,9,10,11.

In L-edge soft X-ray spectroscopy of TM ions, the excitation and ionization of 2p core electrons gives insight into chemical bonding and functionality due to the dipole-allowed probing of frontier d-orbitals. Upon absorption of a soft X-ray photon, a 2p core hole is created at the metal centre; this photon energy is large enough to ionize an electron from the oxygen 1s orbital of the water solvent. Subsequent radiative decay channels of the core-excited TM ion comprise 3d → 2p and 3s → 2p pathways which represent about 1% of the total decay probability for the first-row TM ions12. The majority channel is due to Auger-electron decay; other autoionization processes although being possible13,14,15 will not be considered here.

In pioneering studies16,17,18,19,20,21, L-edge X-ray absorption (XA) spectra from aqueous TM ions have been reported, based, however, solely on the detection of the total fluorescence yield (TFY). The TFY detection mode corresponds to an action spectroscopy. It enjoys popularity since the direct measurement of XA in a transmission experiment is challenging for a liquid-jet with a typical diameter of 10–20 μm1,22,23,24,25. In a TFY measurement, a photodiode is used that integrates the signal from all possible radiative decay channels including the solvent background. However, individual relaxation channels have not been explored separately, with the 3d → 2p one being an exception19,26. In general, the assumption that the detected TFY signal intensity is proportional to the number of initially absorbed X-ray photons at a given excitation photon energy is not valid27,28. There are X-ray optical effects responsible for the deviation between TFY and true XA signals such as concentration-dependent self-absorption and saturation as well as signal/background ratio variation29,30. On a more fundamental level, in order to resemble the first-order XA spectrum the corresponding second-order fluorescence must follow an incoherent two-step model31, and the resulting signal is a product of absorption and emission spectra. This holds true only when the interference effects between different radiative decay channels and non-trivial dependence on the polarization of incoming and detected photons can be neglected. This assumption was found to be violated in several studies27,28. Moreover, the state-dependent electron delocalization into the neighbouring ligands after core-excitation could influence the fluorescence intensity19,20,32. Such charge migration processes may occur on a timescale comparable to the few femtosecond lifetime of the core hole33. These effects together, and our lack of understanding of the role of various decay channels, have caused a fair amount of speculations about the electronic structure which is often calculated by semi-empirical theoretical models34.

Disentangling individual channels requires to resolve the energy of the emitted second-order electrons and photons. This is possible through resonant photoelectron (RPE) spectroscopy for the electron channels, and via resonant inelastic X-ray scattering (RIXS) spectroscopy for photon-decay channels. In the present study, RIXS and RPE experimental techniques are applied together with the first principles restricted active space self-consistent field/second order perturbation theory (RASSCF/RASPT2) calculations in order to explore the complementary character of photon- and electron-emission spectra for the exemplary case of an FeCl2 aqueous solution. The focus is put on the interplay of the decay channels, which is addressed by detecting state-dependent pathways involving 3d valence orbitals versus stronger-bound 3p and 3s iron orbitals. The joint analysis of experimental and theoretical spectra provides two key results. First, the question is answered under which conditions partial-yield photon and electron detection can give an accurate measurement of the true X-ray absorption from TM aqueous solutions. As mentioned before, a transmission spectrum cannot be measured with the present cylindrical microjet, but this has no effect on the analysis of the multiple relaxation channels which is the focus of the present work. Partial fluorescence yield (PFY) and partial electron yield (PEY) spectra are obtained by integration of a signal within photon and electron channel-dependent energy ranges. Second, the basis for a back-to-back analysis of RPE and RIXS measurements from the same FeCl2 aqueous solution is established, providing the assignment of the decay channels and energies of the respective electronic states. It is shown that the joint interpretation of RIXS and RPE spectra for the 3d → 2p channel can considerably contribute to our understanding of solute–solvent interactions.

## Results and Discussion

The XA spectra from the iron aqueous solutions obtained in different partial-yield modes all exhibit L3 (706–715 eV) and L2 (719–726 eV) edge signals arising from the spin-orbit coupling of the 2p core-hole created by X-ray excitation. Figure 1 summarizes the PFY and PEY spectra, obtained for the various decay channels as indicated in the insets. The assignment of the different Auger-electron channels is presented in Figure S1 in the Supplementary Information (SI). The specific relaxation channels differ with respect to the refill of the core-hole which can be either from valence- or core-shells. For photon detection, the signal from Fe 3d → 2p and 3s → 2p relaxation channels was integrated over the emitted photon energy within the channel-dependent energy ranges 660–720 eV and 605–640 eV, respectively. Analogously, photoelectron spectra from 2p3d3d and 2p3p3p Auger decay channels were integrated within 672–715 eV and 560–600 eV kinetic energy ranges, resulting in the respective PEY-XA spectra.

The different decay channels can be classified according to the nature of the involved orbitals. In PFY (Fe 3d → 2p) and PEY (2p3d3d) the electron, which refills the core hole comes from a Fe 3d valence orbital (spectra are denoted as PvFY and PvEY). These 3d orbitals carry information on the mixing with ligand-centred orbitals. In contrast, in PFY (Fe 3s → 2p) and PEY (2p3p3p) the core-hole is refilled by electrons from deeper (3s/3p) Fe orbitals which do not appreciably interact with the ligands (spectra are denoted as PcFY and PcEY).

The calculated PvFY, PcFY spectra, and the transmission XA spectrum shown in Fig. 1a will serve as reference for the following discussion. The two PFY spectra exhibit distinct differences, i.e. the pre-edge intensity near 707 eV excitation photon energy is lower, while the post-edge at 709–714 eV and the L2 edge are more intense for PvFY than for PcFY. The calculated XA and PcFY spectra are essentially indistinguishable from each other. Further, both computed PvFY and PcFY spectra are in very good agreement with the experimental results that are also shown in Fig. 1a. Notice, however, that the calculations did not take into account the X-ray optical effects mentioned above.

The difference in the L3/L2 edge intensity ratio observed in Fig. 1 can be attributed to several effects. These include self-absorption as well as Coster-Kronig transitions, both enhancing the photon emission at the L2 edge4. The fact that these effects are not included into the calculation points to yet another reason for the difference in the spectra, i.e., the spin-orbit coupling. For the two radiative relaxation channels (3s → 2p and 3d → 2p) core-excited intermediate states are mixtures of the wave functions with different multiplicities due to the strong 2p core-hole spin-orbit coupling, whereas valence initial and final states almost do not mix, and represent pure quintet and triplet states. Thus, the second-order fluorescence process, initial → intermediate → final state, can be described as quintet (ground) → mixed → quintet and triplet states, for details see ref. 35. This leads to the appearance of new formally spin-forbidden radiative channels for L3 post-edge and L2 bands, where spin-orbit coupling is stronger than for the lower energy wing of the L3-edge20,26,35. Since spin-orbit coupling has no effect for 3s orbitals and is notable for 3d orbitals, it leads to distortions of PvFY as compared to the XA spectrum, whereas PcFY is not affected. In the following discussion we will focus on the L3 edge only, including its post-edge region.

Compared to the fluorescence yield mode, the PvEY and PcEY spectra (Fig. 1b) show similar although less pronounced differences; see also panels c and d of Fig. 1. The analysis of spin-orbit coupling is more involved in case of PEY, due to transitions between mixed intermediate states of the Fe2+ ion and final valence spin manifolds of the ionized Fe3+ system. Hence, these effects are not considered here.

Another source of differences between PEY/PFY spectra with respect to the transmission XA spectrum is the electronic interaction of the TM ion with the environment, i.e., solvation-shell water molecules. The excited electron can be further involved in other relaxation processes such as electron delocalization and energy transfer20,36. The delocalized excited electron has a lower probability to refill the 2p hole within its lifetime (sub-10 fs), and hence the indirect PEY/PFY probe should be state-dependent according to the extent of delocalization and should not track the true X-ray absorption probability20. The observed behaviour in Fig. 1 thus correlates with the orbital extensions: core 3s and 3p orbitals are strongly localized, and are not or barely involved in iron–ligand orbital mixing. Thus core orbitals are subject to less distortion since delocalization and also spin-orbit channels are of minor importance, while both channels are essential for the 3d shell, since 3d and water lone-pair orbitals are considerably mixed. This behaviour seems to be generally valid, for another example see refs 19,20.

The preceding discussion has pointed to the different sensitivity of valence- and core-level relaxation channels to electron delocalization and spin-orbit coupling. Hence, it is not surprising that PcEY and PcFY detection (Fig. 1c) leads to spectra which are more closely reflecting the true X-ray absorption. Here we argue that the computed XA spectrum accurately captures the true (transmission) XA spectrum; this is yet to be confirmed experimentally though.

In the following we focus on the particular electron- or photon-energy resolved channels involving frontier Fe 3d orbitals. The RPE and RIXS spectra measured at the Fe 2p → 3d resonance are shown in Fig. 2a,b, respectively, in a two-dimensional (2D) representation depending on the incoming photon energy. Panels c and d of Fig. 2 display four cuts through the 2D spectra in the L3-edge region at those excitation energies which correspond to the main absorption features (compare Fig. 1). The theoretical direct photoionization signal from the iron centre contributing to total RPE is shown in Figure S2 of the SI, and the calculated RIXS spectrum is very similar to that discussed in ref. 26.

The RPE spectrum is assigned with the help of the well-understood off-resonant photoelectron spectrum, obtained here at 705 eV excitation energy (see Figs 2c and 3a). It essentially represents the neat-water PE spectrum37,38 with the features at 11.2, 13.5, 17.3, and 31.0 eV binding energies (BE) being due to ionization from the 1b1, 3a1, 1b2, and 2a1 water valence orbitals (blue labels in Fig. 3a), respectively. A very weak signal from Fe 3d at 7.09 eV39 corresponding to the lowest ionization energy of the solution can be also seen.

Since the energetic structure of the valence levels does not depend on the excitation energy, we can discuss the principle features of the RPE spectra for an excitation energy for which signal intensities are strongest. This is the case at maximum absorption, i.e., at 708.4 eV, shown in Fig. 3a. The large Auger-electron signal in the ~8–20 eV BE range, occurring for the Fe L3-edge excitation, mainly arises from the 2p3d3d Auger transition. The Fe 3d orbitals of weakly the tetragonally distorted Jahn-Teller d6 system with approximate D4h point group symmetry split into four components as shown in Fig. 3b. According to the theoretical photoelectron spectrum (Figure S2 of the SI), the Fe transitions (red labels in Fig. 3a) group into three bands: a distinct feature due to ionization of a spin-down (β) electron from the lowest b2g(β) orbital at 7.09 eV BE, a broad band comprising numerous main and combination transitions of spin-up (α) electrons from a1g(α), b1g(α), and eg(α) orbitals overlapping in energy and being centred at 9.5 eV BE, and from b2g(α) at 12.24 eV BE. The b2g(β) electron occupying the deepest 3d orbital has the lowest ionization energy because the orbital binding energy is compensated by pairing (exchange) energy. The chloride 3p valence ionization (green labels in Fig. 3a) leads to a small contribution around 9 eV BE40 coinciding with the Fe a1g(α)/b1g(α)/eg(α) feature as well as with the low-binding energy side of the water 1b1 orbital signal. The feature at 15.3 eV is most probably due to first-solvation shell water 3a1 orbitals, which form σ-bonding combinations with iron a1g and b1g ($dz2$ and $dx2-y2$) orbitals. Note that the 1b2 water signal is also shifted to higher binding energies upon such interactions.

For the resonant excitation at 708.4 eV, the overall RPE signal intensity dramatically increases in comparison to the off-resonant region. Moreover, a signal increase occurs at the energies of the water peaks 1b1, 3a1, and 1b2, and of the Fe 3d peaks. Such a strong signal enhancement results from the interference of the outgoing electron waves from two simultaneous electron emission processes sharing the same final state (see Fig. 3c), and leading to identical kinetic energies of the emitted electrons41,42. One process is the direct ionization of the valence orbitals excited by the 708.4 eV energy photon. The other process is the 2p3d3d Auger-decay releasing a 3d electron from the valence level with the same kinetic energy. This interference effect is a qualitative unequivocal evidence of the mixing between iron and water valence orbitals, and represents a central experimental finding of this study. Note that if there was no mixing, only the Fe 3d signal would be enhanced.

A quantitative comparison of RPE and RIXS spectra in terms of the energies of the occurring peaks requires a proper alignment of both spectra on the energy axis. As a consequence of strong correlation effects and pronounced spin-mixing this requires switching from the one-electron orbital picture to the many-electron states picture as illustrated in Fig. 3c. The lowest-energy peak in the RPE spectrum is due to the transition between ground states of initial Fe2+(aq) and ionized Fe3+(aq) systems for direct ionization or between the X-ray core-excited state of Fe2+(aq) and the ground state of Fe3+(aq) as shown by blue arrows in Fig. 3c. This corresponds to elastic scattering in RIXS when the same core-excited state relaxes back to the ground state of Fe2+(aq) (green arrow in Fig. 3c).

The alignment of the lowest-binding energy RPE feature with the elastic RIXS peak, as is done in Fig. 3a, establishes a common energy reference which allows connecting all other features of the two spectra. Let us consider a particular valence excited state. In RPE, it corresponds to the transition to a final valence excited state of Fe3+(aq) with the excitation energy ΔW (cf. grey arrows in Fig. 3c). Analogously, the inelastic RIXS transition (red arrow) results in a valence excited state of Fe2+(aq) with excitation energy ΔE. If electronic relaxation upon ionization Fe2+(aq) → Fe3+(aq) + e is small and ΔE ≈ ΔW, the present alignment allows the back-to-back comparison and assignment of RPE and RIXS.

According to the suggested alignment, the feature at 2.13 eV loss energy in RIXS is connected with the broad band at 9.5 eV BE in RPE, and thus can be assigned to predominant radiative relaxation from a1g, b1g, and eg orbitals. The RIXS spectral shoulder near 5.13 eV which is in accordance with the 12.24 eV shoulder in RPE can be attributed to the relaxation from the b2g orbital, and a weak band near 9.0 eV loss energy is assigned to weak charge-transfer transitions from first-solvation shell water orbitals. The charge-transfer transitions again evidence the orbital mixing between metal and ligand. Remarkably, the 0.9 eV RIXS feature arises from the relaxation of the same b2g(β) electron as in the first RPE peak. The energy shift of 0.9 eV can be explained taking into account that in RPE the b2g(β) electron is completely removed from the system, and its corresponding Coulomb and exchange energies contribute to the ionization energy. In contrast, in RIXS the energy of the final state is determined by the change of the corresponding terms due to excitation of this electron from b2g to other orbitals. The assignment based on our spectra alignment is supported by the theoretical analysis of the direct photoionization and the RIXS spectra.

Since RPE and RIXS transitions have different selection rules, having a common reference in energy does not imply that the intensities are the same. This explains the absence of prominent RIXS transitions involving water orbitals. Thus, the intensity differences provide information on the rate of different radiative and non-radiative transitions following the core-excitation.

An assignment of the higher-energy excitations, a particularly near 712 eV, where the PEY and PFY spectra exhibit substantially different intensities (Fig. 1), cannot be made based on our spectra. According to the theoretical analysis, this region corresponds to strong mixing between states of different multiplicities, and thus is difficult to interpret taking into account the different influence of spin-orbit coupling onto electron- and photon-out events.

## Conclusions

Complementary electron and photon emission spectra are necessary for a full understanding of electronic-structure interactions between metal solute and water solvent. Previously reported X-ray spectroscopy studies relied on the photon detection and did not consider the electronic structure information from the electron-emission channels. The parallel consideration of PFY and PEY spectra, originating from various channels, reveals large deviations from the true XA spectrum in the case of the 3d → 2p relaxation. In contrast, the “core” PFY and PEY spectra due to the 3s → 2p relaxation are accurate measures of the transmission XA spectrum. In fact our measurements suggest that the latter channel (investigated here for fluorescence) is the most accurate probe. Looking at the 3d → 2p relaxation, with the discussed energy alignment, one can find experimentally find the correspondence between spectral signatures in the RPE and RIXS spectra. Moreover, comparing RPE and RIXS intensities one may obtain information on the competition between the radiative and non-radiative decay channels. Our analysis suggests a new protocol for investigation of X-ray spectra of transition metal solute–solvent electronic interactions. The provided insight shall promote understanding structure and rational design of catalytic and other functional materials.

## Experimental

FeCl2 hexahydrate salt, purchased from Sigma Aldrich with >99% purity, was dissolved in deionised water to make a 1 M aqueous solution for both photon and electron measurements. The colour of the solution is pale-lime and the molar ratio of [Fe(H2O)5Cl]+ and [Fe(H2O)6]2+ species is ~77/23 43,44. The microjet technique was employed to introduce the liquid sample into the vacuum chamber through a 20 μm diameter glass nozzle. The electron and photon signals were taken from the laminar area of the jet which is approximately 2–3 mm in length starting from the nozzle head.

The experiments were carried out at the U41-PGM undulator beamline at the synchrotron facility BESSY II, Berlin. Two experimental stations, LiXEdrom and LiquidPES, were used for photon and electron detection, respectively. The U41-PGM beamline provides horizontally linear polarized light with high photon flux and a micro-focus spot, which is crucial to micro-jet measurements. In LiXEdrom, photons emitted from the jet were collected along the polarization direction of the incident photon beam (to suppress the elastic peak) and subsequently dispersed by a spherical grating with 1200 lines/mm and 7.5 m radius. The dispersed photons were then detected by a microchannel plate (MCP)/fluorescence screen/CCD assembly. The sample, grating, and photon detector are arranged on a Rowland circle geometry for accurate focusing. For the LiquidPES experiment, electrons were collected perpendicular to the polarization of the incident photon beam by a hemispherical energy analyzer. Note that the 2p3s3s Auger-decay channel is not considered because of a too low signal. The details of the two experimental stations have been described elsewhere1,2,3,4.

## Computational

Theoretical calculations were performed for [Fe(H2O)6]2+ and [Fe(H2O)5Cl]+ complexes, where geometries were optimized at the BLYP/cc-pVTZ level with Gaussian 09 package45. The valence- and core-excited electronic states were further studied using the restricted active space self-consistent field (RASSCF) method46 with the relativistic ANO-RCC basis sets47,48 of triple-zeta quality. The second order perturbation theory correction (RASPT2) with an imaginary level shift of 0.1 Hartree was applied on top of RASSCF to account for dynamic correlation. The active space for XAS, RIXS, and PFY calculations included 2p in the RAS1 space (1 hole allowed) and 3s together with 3d orbitals in RAS2 space (full CI); all occupied inactive orbitals were kept frozen. The resulting configuration space includes dipole-allowed 2p → 3d excitations and 3d → 2p and 3s → 2p radiative relaxation transitions. Spin-orbit coupling was treated in the LS-coupling limit49 taking into account 75 quintet (S = 2) and 375 triplet (S = 1) directly interacting states. Scalar relativistic effects were included within the Douglas-Kroll-Hess approach50,51. RIXS and PFY spectra were evaluated using the Kramers-Heisenberg expression properly including coherence effects and polarization dependence (for details, see ref. 35). Valence photoelectron spectra were obtained using the Dyson orbital approach as described in ref. 52 with the active space including only 3d orbitals in RAS2 space. A single quintet initial state for [Fe(H2O)6]2+ and 1 sextet (S = 5/2), 24 quartet (S = 3/2), and 75 doublet (S = 1/2) final states coupled via spin-orbit coupling were included for [Fe(H2O)6]3+. All calculations were performed with a locally modified MOLCAS 8.0 code53.

How to cite this article: Golnak, R. et al. Joint Analysis of Radiative and Non-Radiative Electronic Relaxation Upon X-ray Irradiation of Transition Metal Aqueous Solutions. Sci. Rep. 6, 24659; doi: 10.1038/srep24659 (2016).

## References

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& Photoemission from liquid aqueous solutions. Chem. Rev. 106, 1176–1211 (2006).

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Liquid microjet for photoelectron spectroscopy. Nucl. Instrum. Methods Phys. Res. Sect. Accel. Spectrometers Detect. Assoc. Equip. 601, 139–150 (2009).

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et al. High resolution X-ray emission spectroscopy of water and aqueous ions using the micro-jet technique. Chem. Phys. 377, 1–5 (2010).

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et al. Probing Coster-Kronig transitions in aqueous Fe2+ solution using inverse partial and partial fluorescence yield at the L-edge. J. Phys. Chem. Lett. 3, 1619–1623 (2012).

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, & Fischer-Tropsch catalysis: The basis for an emerging industry with origins in the early 20th century. Catal. Today 145, 38–44 (2009).

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et al. Light-driven hydrogen generation: Efficient iron-based water reduction catalysts. Angew. Chem. Int. Ed. 48, 9962- 9965 (2009).

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Effect of ions on the structure of water: Structure making and breaking. Chem. Rev. 109, 1346–1370 (2009).

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& Ionic liquids—new “solutions” for transition metal catalysis. Angew. Chem. Int. Ed. 39, 3772–3789 (2000).

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et al. Selective oxidation of methane to synthesis gas using transition metal catalysts. Nature 344, 319–321 (1990).

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& Asymmetric transfer hydrogenation of ketones with bifunctional transition metal-based molecular catalysts. Acc. Chem. Res. 40, 1300–1308 (2007).

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& Resonant inelastic X-ray scattering spectra for electrons in solids. Rev. Mod. Phys. 73, 203–246 (2001).

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et al. Charge dependence of solvent-mediated intermolecular Coster-Kronig decay dynamics of aqueous ions. J. Phys. Chem. B 114, 17057–17061 (2010).

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et al. Ionic-charge dependence of the intermolecular coulombic decay time scale for aqueous ions probed by the core-hole clock. J. Am. Chem. Soc. 133, 13430–13436 (2011).

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, & Ultrafast charge delocalization dynamics in aqueous electrolytes: New insights from Auger electron spectroscopy. Chem. Phys. Lett. 543, 1–11 (2012).

16. 16.

The solvation of ions and molecules probed via soft X-ray spectroscopies. J. Electron Spectrosc. Relat. Phenom. 177, 168–180 (2010).

17. 17.

, , & Soft X-ray absorption spectroscopy in liquid environments. J. Electron Spectrosc. Relat. Phenom. 137–140, 413–416 (2004).

18. 18.

et al. A liquid flow cell to study the electronic structure of liquids with soft X-rays. Nucl. Instrum. Methods Phys. Res. Sect. Accel. Spectrometers Detect. Assoc. Equip. 585, 172–177 (2008).

19. 19.

et al. Origin of dark-channel X-ray fluorescence from transition-metal ions in water. J. Am. Chem. Soc. 134, 1600–1605 (2012).

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, , , & State-dependent electron delocalization dynamics at the solute-solvent interface: Soft X-ray absorption spectroscopy and ab initio calculations. Phys. Rev. Lett. 111, 083002 (2013).

21. 21.

, , , & Development of a liquid flow cell to measure soft X-ray absorption in transmission mode: A test for liquid water. J. Electron Spectrosc. Relat. Phenom. 177, 130–134 (2010).

22. 22.

& ESCA applied to liquids. J. Electron Spectrosc. Relat. Phenom. 2, 319–325 (1973).

23. 23.

, & Photoelectron spectroscopy of liquid water, some alcohols, and pure nonane in free micro jets. J. Chem. Phys. 106, 9013 (1997).

24. 24.

, & Chemistry in solution: Recent techniques and applications using soft X-ray spectroscopy. Phys. Chem. Chem. Phys. 14, 5331–5338 (2012).

25. 25.

et al. X-ray spectroscopy of liquid water microjets. J. Phys. Chem. B 105, 3346–3349 (2001).

26. 26.

et al. The nature of the chemical bond of aqueous Fe2+ probed by soft X-ray spectroscopies and ab initio calculations. J. Phys. Chem. B 117, 12613–12618 (2013).

27. 27.

, , , & Fluorescence yield detection: Why it does not measure the X-ray absorption cross section. Solid State Commun. 92, 991–995 (1994).

28. 28.

et al. Intrinsic deviations in fluorescence yield detected X-ray absorption spectroscopy: The case of the transition metal L2,3 edges. J. Phys.: Condens. Matter 24, 452201 (2012).

29. 29.

Dips and peaks in fluorescence yield X-ray absorption are due to state-dependent decay. Nat. Chem. 4, 766–767 (2012).

30. 30.

, , & & Hawthorn, D. G. Dark channel fluorescence observations result from concentration effects rather than solvent-solute charge transfer. Nat. Chem. 4, 765–766 (2012).

31. 31.

, & Polarization anisotropy in resonant X-ray emission from molecules. Phys. Rev. A 53, 1340–1348 (1996).

32. 32.

, , , & Charge transfer to solvent identified using dark channel fluorescence-yield L-edge spectroscopy. Nat. Chem. 2, 853–857 (2010).

33. 33.

& Radiation generated by the ultrafast migration of a positive charge following the ionization of a molecular system. Phys. Rev. Lett. 106, 053001 (2011).

34. 34.

& Core level spectroscopy of solids. (CRC Press, Boca Raton, 2008).

35. 35.

et al. Unraveling the electronic structure of photocatalytic manganese complexes by L-edge X-ray spectroscopy. J. Phys. Chem. C 119, 19192–19200 (2015).

36. 36.

et al. On the nature and origin of dicationic, charge-separated species formed in liquid water on X-ray irradiation. Nat Chem 5, 590–596 (2013).

37. 37.

et al. Full valence band photoemission from liquid water using EUV synchrotron radiation. J. Phys. Chem. A 108, 2625–2632 (2004).

38. 38.

et al. Photoelectron spectroscopy of aqueous solutions: Streaming potentials of NaX (X = Cl, Br, and I) solutions and electron binding energies of liquid water and X. J. Chem. Phys. 140, 174506 (2014).

39. 39.

et al. Valence photoemission spectra of aqueous Fe2+/3+ and [Fe(CN)6]4−/3− and their interpretation by DFT calculations. J. Phys. Chem. B 115, 11671–11677 (2011).

40. 40.

et al. Electron binding energies of aqueous alkali and halide ions: EUV photoelectron spectroscopy of liquid solutions and combined ab initio and molecular dynamics calculations. J. Am. Chem. Soc. 127, 7203–7214 (2005).

41. 41.

, , , & Ultrafast hybridization screening in Fe3+ aqueous solution. J. Am. Chem. Soc. 133, 12528–12535 (2011).

42. 42.

Photoelectron spectroscopy: Principles and applications, 3 ed. (Springer-Verlag, Berlin Heidelberg, 2003).

43. 43.

& A spectrophotometric study of aqueous iron (ii) chloride complexing from 25 to 200 °C. Geochim. Cosmochim. Acta 54, 2207–2221 (1990).

44. 44.

, & Structure and specification of iron complexes in aqueous solutions determined by X-ray absorption spectroscopy. Geochim. Cosmochim. Acta 49, 2081–2089 (1985).

45. 45.

et al. Gaussian 09, revision C.1 (Gaussian, Inc., Wallingford CT, 2009).

46. 46.

, & The restricted active space self-consistent-field method, implemented with a split graph unitary group approach. J. Phys. Chem. 94, 5477–5482 (1990).

47. 47.

, , , & Main group atoms and dimers studied with a new relativistic ANO basis set. J. Phys. Chem. A 108, 2851–2858 (2004).

48. 48.

, , , & New relativistic ANO basis sets for transition metal atoms. J. Phys. Chem. A 109, 6575–6579 (2005).

49. 49.

, & The restricted active space (RAS) state interaction approach with spin-orbit coupling. Chem. Phys. Lett. 357, 230–240 (2002).

50. 50.

& Quantum electrodynamical corrections to the fine structure of helium. Ann. Phys. 82, 89–155 (1974).

51. 51.

Relativistic electronic-structure calculations employing a two-component no-pair formalism with external-field projection operators. Phys. Rev. A 33, 3742–3748 (1986).

52. 52.

et al. Multi-reference approach to the calculation of photoelectron spectra including spin-orbit coupling. J. Chem. Phys. 143, 074104 (2015).

53. 53.

et al. Molcas: A program package for computational chemistry. Comput. Mater. Sci. 28, 222–239 (2003).

## Acknowledgements

S.I.B, G.G., S.G.A. and O.K. acknowledge financial support by the Deanship of Scientific Research (DSR), King Abdulaziz University, Jeddah, (grant No. D-003-435) and the Deutsche Forschungsgemeinschaft (KU 952/10-1). K.A. acknowledges financial support of the Einstein Foundation Berlin for a postdoctoral scholarship. B.W. and R.S. gratefully acknowledge support from the Deutsche Forschungsgemeinschaft (Collaborative Research Centre 1109), and B.W. also gratefully acknowledges support from the Deutsche Forschungsgemeinschaft Research Unit FOR 1789. The authors thank the HZB staff for assisting in the operation of the beamline.

## Affiliations

1. ### Institute of Methods for Material Development, Helmholtz-Zentrum Berlin, Albert-Einstein-Straße 15, D-12489 Berlin, Germany

• Ronny Golnak
• , Robert Seidel
• , Jie Xiao
• , Kaan Atak
• , Isaak Unger
• , Bernd Winter
2. ### Department of Chemistry, Freie Universität Berlin, Takustraße 3, D-14159 Berlin, Germany

• Ronny Golnak
3. ### Institut für Physik, Universität Rostock, D-18051 Rostock, Germany

• Sergey I. Bokarev
• , Gilbert Grell
•  & Oliver Kühn
4. ### Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan

• Stephan Thürmer

## Contributions

B.W. and E.F.A. conceived and designed experiments. R.G., R.S., J.X., K.A., I.U. and S.T. conducted experiments and analyzed the data. S.I.B. and G.G. performed theoretical calculations. E.F.A., S.G.A. and O.K. coordinated the project. S.I.B., R.S., J.X., O.K. and B.W. co-wrote the paper; all authors were involved in the discussion and preparation of the manuscript.

## Competing interests

The authors declare no competing financial interests.

## Corresponding authors

Correspondence to Sergey I. Bokarev or Bernd Winter or Emad F. Aziz.

1. 1.


text:
# Safely using console.* in browser

I come from a Java background so my desire for proper unambiguous logging is strong. I prefer using the console to using some other gui widget however, in the browser I know that I can't always count on the console to exist or for it to have all the levels I might like. To remedy this I worked up the following console sanitizer and I was curious what drawbacks it might have.

function configureConsoleLog() {
"use strict";
var logMethods = [ 'trace', 'debug', 'log', 'info', 'warn', 'error' ], i;

if (!window.console) {
window.console = {log: function (args) {}}; //noop
}

for (i = 0; i < logMethods.length; i += 1) {
if (!window.console[logMethods[i]]) {
window.console[logMethods[i]] = window.console.log;
}
}
}

The idea is to find out if console exists and if it does try to find out which of the supported levels I need are available. The first level of fallback is to map unsupported methods to console.log. The second level is to create my own console variable and make a noop log function since I have nowhere to send the output. This approach leaves open the possibility of coming up with a different strategy if console doesn't exist but for now I'm content to ignore logging if there is no console.

As a side note I looked at several JS logging packages but all of them have the fatal drawback of obscuring original line numbers, usually by delegating to a console method which only reports the line number of the delegating statement.

Thoughts?

• I think I saw a really good discussion of this exact problem. Perhaps on StackExchange - did you check there? – Donald.McLean Apr 25 '12 at 4:32
• I have searched a bit but couldn't find anything that matched my problem. However, I will take another look on SO. – adambender Apr 25 '12 at 4:33
• The post I saw was this one: stackoverflow.com/questions/690251/… (I meant StackOverflow in my comment) – Donald.McLean Apr 25 '12 at 15:46
• Looks like the advice is consistent with my approach, thanks for the pointer. – adambender Apr 25 '12 at 16:56

I don't see any problems with that. It's similar to this answer on SO.

Just a couple minor things:

• You don't need args in the empty log function

• You should make the entire function anonymous and execute it immediately (as it's being done in the answer I linked to); I don't think there's any usecase for calling it otherwise

• Don't forget var in front of the i variable, otherwise it becomes global

• First, thanks for the tips! I think args was actually vestigial and definitely should be removed. This particular function is being called from inside of another framework as a part of a config/bootstrap process so it works best as a function in this case. Lastly, the i variable is declared at the top of the function (jslint enforced), it's just hanging on the end of the array initialization, probably should be moved to the front so it doesn't get lost. – adambender Apr 25 '12 at 16:52
• @adambender: ah yeah, I missed the i at the end :) – seand Apr 25 '12 at 16:55


text:
# NAG Library Function Document

## 1Purpose

nag_ode_bvp_ps_lin_coeffs (d02uac) obtains the Chebyshev coefficients of a function discretized on Chebyshev Gauss–Lobatto points. The set of discretization points on which the function is evaluated is usually obtained by a previous call to nag_ode_bvp_ps_lin_cgl_grid (d02ucc).

## 2Specification

 #include #include
 void nag_ode_bvp_ps_lin_coeffs (Integer n, const double f[], double c[], NagError *fail)

## 3Description

nag_ode_bvp_ps_lin_coeffs (d02uac) computes the coefficients ${c}_{\mathit{j}}$, for $\mathit{j}=1,2,\dots ,n+1$, of the interpolating Chebyshev series
 $12 c1 T0 x- + c2 T1 x- + c3T2 x- +⋯+ cn+1 Tn x- ,$
which interpolates the function $f\left(x\right)$ evaluated at the Chebyshev Gauss–Lobatto points
 $x-r = - cos r-1 π/n , r=1,2,…,n+1 .$
Here ${T}_{j}\left(\stackrel{-}{x}\right)$ denotes the Chebyshev polynomial of the first kind of degree $j$ with argument $\stackrel{-}{x}$ defined on $\left[-1,1\right]$. In terms of your original variable, $x$ say, the input values at which the function values are to be provided are
 $xr = - 12 b - a cos πr-1 /n + 1 2 b + a , r=1,2,…,n+1 , $
where $b$ and $a$ are respectively the upper and lower ends of the range of $x$ over which the function is required.

## 4References

Canuto C (1988) Spectral Methods in Fluid Dynamics 502 Springer
Canuto C, Hussaini M Y, Quarteroni A and Zang T A (2006) Spectral Methods: Fundamentals in Single Domains Springer
Trefethen L N (2000) Spectral Methods in MATLAB SIAM

## 5Arguments

1:    $\mathbf{n}$IntegerInput
On entry: $n$, where the number of grid points is $n+1$. This is also the largest order of Chebyshev polynomial in the Chebyshev series to be computed.
Constraint: ${\mathbf{n}}>0$ and n is even.
2:    $\mathbf{f}\left[{\mathbf{n}}+1\right]$const doubleInput
On entry: the function values $f\left({x}_{\mathit{r}}\right)$, for $\mathit{r}=1,2,\dots ,n+1$.
3:    $\mathbf{c}\left[{\mathbf{n}}+1\right]$doubleOutput
On exit: the Chebyshev coefficients, ${c}_{\mathit{j}}$, for $\mathit{j}=1,2,\dots ,n+1$.
4:    $\mathbf{fail}$NagError *Input/Output
The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

## 6Error Indicators and Warnings

NE_ALLOC_FAIL
Dynamic memory allocation failed.
See Section 2.3.1.2 in How to Use the NAG Library and its Documentation for further information.
On entry, argument $〈\mathit{\text{value}}〉$ had an illegal value.
NE_INT
On entry, ${\mathbf{n}}=〈\mathit{\text{value}}〉$.
Constraint: ${\mathbf{n}}>1$.
On entry, ${\mathbf{n}}=〈\mathit{\text{value}}〉$.
Constraint: n is even.
NE_INTERNAL_ERROR
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 2.7.6 in How to Use the NAG Library and its Documentation for further information.
NE_NO_LICENCE
Your licence key may have expired or may not have been installed correctly.
See Section 2.7.5 in How to Use the NAG Library and its Documentation for further information.

## 7Accuracy

The Chebyshev coefficients computed should be accurate to within a small multiple of machine precision.

## 8Parallelism and Performance

nag_ode_bvp_ps_lin_coeffs (d02uac) is threaded by NAG for parallel execution in multithreaded implementations of the NAG Library.
nag_ode_bvp_ps_lin_coeffs (d02uac) makes calls to BLAS and/or LAPACK routines, which may be threaded within the vendor library used by this implementation. Consult the documentation for the vendor library for further information.
Please consult the x06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this function. Please also consult the Users' Note for your implementation for any additional implementation-specific information.

The number of operations is of the order $n\mathrm{log}\left(n\right)$ and the memory requirements are $\mathit{O}\left(n\right)$; thus the computation remains efficient and practical for very fine discretizations (very large values of $n$).


text:
can interaction between a massless fermion and external sourse exist?

For example, let's consider the electromagnetic interaction between a massless fermion and a electromagnetic externel sourse $A^\mu$, then the lagrangian is $$\mathcal{L}=\bar{\psi}\gamma^\mu\partial_\mu\psi+ieA_\mu\bar{\psi}\gamma^\mu\psi$$ and how can we calculate the Feynman diagram and $\mathcal{M}$ of it?

But according to relativity, the equation of motion of a particle with charge is $$e F^a\ _bU^b=U^b\partial_bP^a$$ where $F_{ab}$ is the electromagnetic tensor, $U^a$ is the 4-velocity of the particle and $P^a$ is the 4-momentum of the particle. If the particle is massless, then the speed will be $1$ and this equation fails.

So can a massless particle have charge and interaction with externel sourse? If could, for example, how can I calculate the force and equation of motion? If couldn't, why?

I think, you are mixing quantum electrodynamics with classical (relativistic) electrodynamics. The equation of motion you stated above is from the classical electrodynamics where particles are considered point charges. In quantum electrodynamics particles are just field excitation, so you cannot ask for their four-velocity but rather for the time evolution of the field configuration of the corresponding field. In this case you are interested in the fermionic field $\Psi$ which is described by the Dirac equation. You can derive it from the lagrangian above by applying the Euler Lagrange equations. When solving the Dirac equation you will typically be forced to go into Fourier space and therefore deal with Fourier modes rather than with the field configuration in space-time, which usually leads to computing cross sections of scattering between plain waves (i.e. Fourier modes) of the $A$ and the $\Psi$ field.


text:
# Pi,Pi,Pi!

Find the first $$20$$ digit prime in consecutive digits of $$\pi$$.

This problem was inspired by Agnishom's problem: Google,Euler's Number and the Hidden Prime.

×


text:
# Release Notes

#### Release 4.13.2

##### Prerequisites

Before installing ExactAccess 4.13.2, please ensure that the following requirements are met:

• On Client systems:

• .Net Framework 4.7 or higher

• .Net Core Framework Windows Desktop Runtime 3.1.x or higher

• .Net Core Framework ASP.Net 3.1.x or higher

• On Server systems:

• None

##### Supported Operating Systems

XA Client supports Windows 10 and Windows 11 (Windows 11 support was added in this release)

XA Server supports Windows Server 2016 and Windows Server 2019

##### Notable Improvements
• Added support in extension to save credentials for submitting form upon pressing Enter (HEALTH-158, HEALTH-276)

• Added feature to block specific URLs for a domain by adding partial URL matching. To configure this feature, see "FAQ Question 1". (HEALTH-268)

##### Fixes
• Added support for SnapApp to work while switching between test server to the production server (HEALTH-87)

• Resolved issue of detecting any fields within all websites in the same domain when the URL is changing (HEALTH-90)

• Updated extension manifest files location to XA software installation directory. Also moved related registry settings from HKCU to HKLM. (HEALTH-4)

• Corrected saving and fetching Auto-Submit setting to handle auto-submit feature for sites for Chromium & Firefox browsers (HEALTH-28)

• Fixed in Chrome & Firefox NTLM files to handle SnapApp extension's behavior with NTLM sites (HEALTH-159)

• Fixed issue related to disconnecting current user's session while tapping card user on Citrix receiver end (HEALTH-362)

### Note

If the first user takes 1.5-2 minutes' time on the Hyperspace window after logging in to Hyperspace, and after that, a second user taps over the session, then only the current user will show in Task Manager and there will be no issues.

• Badge scanning was disabled on Windows log out or tap over (HEALTH-363)

##### Backward Compatibility
• Upgrade from 4.11.6 to 4.13.1 or to 4.13.2 is supported

• Upgrade from 4.12.5 to 4.13, or to 4.13.1, or to 4.13.2 is supported

• Upgrade from 4.13.0 to 4.13.1 or to 4.13.2 is supported

• Upgrade from 4.13.1 to 4.13.2

##### FAQs

Question: How do I disable SnapApp extension to ignore a specific webpage (e.g. password reset, forgot password, etc.)?

Solution: We have to add a DisablePageSSO registry setting to disable SnapApp extension to ignore a specific webpage (e.g. password reset, forgot password, etc.).

Follow these steps to cause SnapApp to ignore a specific webpage:

##### Example

In this example, we have a domain cloud.tenable.com on which we want to disable the SnapApp extension for some pages/URLs.

We have two URLs: a Login Page URL and a Forgot/Reset Password Page URL.

### Note

There is a dynamic part after the word "password-reset" on this URL. This could be anything like a user ID, category info, or a GUID. We have to exclude that part of the URL when adding it to the DisablePageSSO setting in the registry.

Case 1: When a user enters the login page URL, it will not match the existing URL in the registry. So SnapApp will work as usual.

Case 2: When a user enters the password reset page URL, it will match with the existing URL in the registry with the help of the Wild Card Pattern Matching process. We check the registry URL with an asterisk (*-the wildcard used in matching) included at the end of the URL that the user has entered. In this case, the user's URL will match with the existing one, and SnapApp will disable for that page and will not fetch & set credentials there.

### Note

DisablePageSSO setting is an advanced setting for SnapApp and will not be in the registry by default. If we want this feature, we have to add this setting under SnapAPP Settings in the registry.

1. On a client system with XA Client installed, open the registry editor and navigate to this path:

1. Computer\HKEY_LOCAL_MACHINE\SOFTWARE\HealthCast\eXactACCESS\SnapAPP Settings

2. Create a new key under SnapApp Settings and set its name to DisablePageSSO.

3. Next, under DisablePageSSO, create a new key with the name of the domain of the relevant site.

### Note

Ensure you only use the domain name without any www, HTTP, or https.

4. Next, for the domain name key, add the specific URLs as string values in the right panel as shown below.

### Note

URLs added here should NOT contain the dynamic part, like any query string value or any parameter for username or ID.

5. SnapApp will check for the DisablePageSSO setting in the registry and then will check for the domains. If the domain of the current URL exists in this list, then SnapApp will check for the blocked URLs for that specific domain and will exclude those URLs from its default behavior, meaning it will not fetch and set credentials for that URL.

6. This process uses Wild Card Pattern Matching to match the current URL with the partial URLs specified here.