# Z-expansion of matrix elements of one-electron operators for many-electron atoms

## Description

Title of program: SSTR-TRANSITION GENERALIZED SUMS Catalogue Id: AACH_v1_0 Nature of problem Program SSTR (Substitution Sums for Transitions), computes the generalized single-particle substitution sums used in obtaining the coefficient of the second term in the Z-expansion of the matrix elements of one-electron operators in many-electron atoms. The calculations correspond in complexity to those needed for the contributions E'_2 in the second-order energy, but not to those needed for E''_2. The program is generalized to use one-electron operators corresponding to r^kk, for brevity referre ... Versions of this program held in the CPC repository in Mendeley Data AACH_v1_0; SSTR-TRANSITION GENERALIZED SUMS; 10.1016/0010-4655(79)90028-6 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)