Theoretical study of level structure and transitions of configurations 3d94s2, 3d94s4p, 3d94p2 for Nb XIII

Fine-structure energy levels of two-electron excitation configurations 3d(9)4s(2), 3d(9)4s4p, 3d(9)4p(2) are calculated by Hartree-Fock method, which includes the configuration interaction, relativistic correction and approximate Breit correction, for copper-like Nb XIII. More accurate levels are obtained by the least-square-fit technique. The wavelengths and transition probabilities of 3d(9)4s4p-3d(10)4s, 3d(9)4s(2)-3d(10)4p, 3d(9)4p(2)-3d(10)4p, 3d(9)4s4p-3d(9)4s(2) transition array are obtained, and some unknown results are predicted. Computing research shows that the 40.92 nm line should belong to 3d(9)4s(D-1)4p F-2(7/2)-3d(9)(2D)4s(2) D-2(5/2) transition, but not to the 3d(9)4s(D-1)4p D-4(7/2)-3d(9)(D-2)4s(2) D-2(5/2) transition, and the upper term level should be F-2(7/2), but not D-4(7/2).