Influence of exchange distortion potential on electron impact excitation of B+

The relativistic distorted-wave method was used to calculate electron impact excitation of B+. The target states were described by a 133-level MCDF configuration-expansion. The relativistic continuum orbitals were calculated in the potential field of the frozen target-ion charge distribution. The semiclassical and free-electron-gas approximations of Riley and Truhlar and the Dirac–Fock–Slater (DFS) approximation were used in the calculation of exchange distortion potentials. It is found that the exchange potentials have significant influence on collision strengths especially for spin-forbidden transitions. In particular, DFS potentials are less suitable compared with the other potentials.