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tokens: et al. 2013 ). Moreover, Cleeves et al. ( 2015 ) show that reduced cosmic ray ionization (a consequence of exclusion by disc winds) produce disc chemistry features in agreement with TW Hya observations. Our population results showing that X-ray ionized models produce populations that better reproduce observational features are in agreement with these results. One key difference in our super Earth populations and the observations is that our model produces fewer close-in super Earths. When comparing the direct population outputs (Fig. 10 ) with the populations that account for observational biases (Fig. 9 ), we see that a portion of the zone 5 planets in our model are filtered out as they have low observation probabilities. Additionally, our model does produce a large number of failed cores, but a significant fraction of these orbit just outside the defined outer observable limit of 2 au, and are situated on orbits out to 5 au. The range of radii between 1 and 5au is the most common region for super Earths to form in our model as this is the region where the ice line, heat transition, and cosmic ray dead zone traps converge to. Thus, our model predicts there to be a significant population of super Earths with orbital radii of 1–5 au. Our planet formation model does not produce low mass super Earths that migrate into short-period orbits. We noted this several times throughout Section 4 and refer to this as a zone of avoidance of our model within zone 5 of the mass-semimajor axis diagram. The lowest mass super Earths formed in our model that populate zone 5 are ∼3 M ⊕ and orbit outside of 1 au. This feature of our populations is tied to the evolution of the traps that evolve from orbital radii outside ∼8 au to within ∼1 au on disc evolution time-scales. This prevents ∼Earth-mass planets from migrating to short period orbits in our model as they evolve with the trap they are forming within. Planets can, however, become liberated from their host planet traps at the onset of type II migration. In this case, planets must exceed their gap opening mass (equation 17 ) of ∼10 M ⊕ to type II migrate separately from their trap. Initially, type II migration takes place on shorter time-scales than trapped type I migration, so these planets can, in some cases, migrate to short period orbits during their slow gas accretion phase before their accretion is terminated at the disc lifetime. Thus, the lowest mass zone 5 planets orbiting between 0.01 and 0.1au formed in our model have masses ≳10 M ⊕ . Hasegawa ( 2016 ) also found that a core accretion model involving trapped type I migration could not form a failed core population consistent with observations. In particular, this model could only form super Earths more massive than ∼4–5 M ⊕ , similar to the results found in this work. Based on the results of our constant dust-to-gas ratio model, one might suggest that formation scenarios in addition to the failed core scenario are necessary to explain the observed