Transition frequencies between 2S and 2P states of lithium-like ions


 The Schrödinger equation for the $2S$ and $2P$ states of the lithium-like ions $Z=5-7,9-10$ is solved by using the Rayleigh-Ritz variational method in Hylleraas coordinates. The leading-order relativistic and QED corrections are calculated perturbatively and higher-order corrections are estimated. The transition frequencies between the $2S_{1/2}$ and $2P_J$ ($J=1/2,3/2$) states are determined and compared with experimental and other theoretical results. Specifically, isotope shifts are also calculated for B$^{2+}$.