# Multiconfiguration electron density function for the ATSP2K-package

## Description

Abstract A new atsp2K module is presented for evaluating the electron density function of any multiconfiguration Hartree–Fock or configuration interaction wave function in the non-relativistic or relativistic Breit–Pauli approximation. It is first stressed that the density function is not a priori spherically symmetric in the general open shell case. Ways of building it as a spherical symmetric function are discussed, from which the radial electron density function emerges. This function is written in... Title of program: DENSITY Catalogue Id: AEFR_v1_0 Nature of problem This program determines the atomic electronic density in the MCHF (LS ) or Breit-Pauli (LS J) approximation. It also evaluates the natural orbitals by diagonalizing the density matrix. Versions of this program held in the CPC repository in Mendeley Data AEFR_v1_0; DENSITY; 10.1016/j.cpc.2009.10.014 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018)