A program for accurate solutions of two-electron atoms

Abstract We present a comprehensible computer program capable of treating non-relativistic ground and excited states for a two-electron atom having infinite nuclear mass. An iterative approach based on the implicitly restarted Arnoldi method (IRAM) is employed. The Hamiltonian matrix is never explicitly computed. Instead the action of the Hamiltonian operator on discrete pair functions is implemented. The finite difference method is applied and subsequent extrapolations gives the continuous grid resul... Title of program: corr2el Catalogue Id: ADUX_v1_0 Nature of problem The Schrödinger equation for two-electron atoms is solved using finite differences. Versions of this program held in the CPC repository in Mendeley Data ADUX_v1_0; corr2el; 10.1016/j.cpc.2004.01.007 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)