Relativistic distorted-wave collision strengths for the 16Δn=0 optically allowed transitions with n=2n=2 in the 67 Be-like ions with 26≤Z≤9226≤Z≤92

Relativistic distorted-wave collision strengths have been calculated for the 16 Δn=0Δn=0 optically allowed transitions with n=2n=2 in the 67 Be-like ions with nuclear charge number ZZ in the range 26≤Z≤9226≤Z≤92. The calculations were made for the four final, or scattered, electron energies E′=0.20E′=0.20, 0.42, 0.80, and 1.40, where E′E′ is in units of Zeff2 Ry with Zeff=Z−2.5. In the present calculation, an improved “top-up” method, which employs relativistic plane waves, was used to obtain the high partial-wave contribution for each transition, in contrast to the partial-relativistic Coulomb–Bethe approximation used in previous work by Zhang and Sampson [H.L. Zhang and D.H. Sampson, At. Data Nucl. Data Tables 52 (1992) 143]. In that earlier work, collision strengths were also provided for Be-like ions, but for a more comprehensive data set consisting of all 45 Δn=0Δn=0 transitions, six scattered energies, and the 85 ions with ZZ in the range 8≤Z≤928≤Z≤92. The collision strengths covered in the present work should be more accurate than the corresponding data given by Zhang and Sampson [H.L. Zhang and D.H. Sampson, At. Data Nucl. Data Tables 52 (1992) 143] and are presented here to replace those earlier results.