Contribution of three-electron diagrams of two-photon exchange to the energy of 2s, 2p1sol2, and 2p3sol2 states of Li-like multiply charged ions

The contribution of three-electron diagrams of two-photon exchange to the energy of 2s, 2p1sol2, and 2p3sol2 states of Li-like ions is calculated. The consistent quantum-electrodynamic calculation is performed for the nuclear charge Z varying over a wide range with the correction for the finite size of the nucleus taken into account. All the contributions to the energy of the 2p1sol2-2s transition in Li-like ions with Z ≥ 18 calculated to date are collected