# REOS99: A revised program for transition probability calculations including relativistic, correlation, and relaxation effects

## Description

Abstract Recent years have seen an increasing demand on accurate transition probability calculations for open-shell atoms and ions. To facilitate such investigations, the program REOS [S. Fritzsche, C.F. Fischer, Comput. Phys. Commun. 99 (1997) 323] has been developed which includes the effects of relativity, correlation, and the rearrangement of the bound-state electron density within the framework of the multiconfiguration Dirac–Fock model. Often, however, very large wave function expansions are ind... Title of program: REOS99 Catalogue Id: ADEJ_v2_0 [ADLF] Nature of problem Transition probability calculations for (open-shell) atoms have shown that large wave function expansions are often needed to obtain sufficient accurate results. For ab-initio calculations, these wave functions must include the effects of relativity, electron correlations, and the rearrangement of the electron density within a common framework. The REOS99 program accounts for all of these effects for the computation of Einstein coefficients, oscillator strengths, and (radiative) lifetimes. It ap ... Versions of this program held in the CPC repository in Mendeley Data ADEJ_v1_0; REOS; 10.1016/S0010-4655(96)00116-6 ADEJ_v2_0; REOS99; 10.1016/S0010-4655(99)00453-1 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)