On the inclusion of the Breit interaction term in the closed-shell generator coordinate Dirac–Fock formalism

Abstract

The generator coordinate Dirac–Fock formalism with the inclusion of the frequency-independent Breit interaction term is presented. The integration of the Dirac–Fock equations is performed through an integral discretization technique in order to preserve the continuous character of the original generator coordinate formalism. The inclusion of the Breit interaction term in the generator coordinate Dirac–Fock formalism is assessed through Dirac–Fock–Breit calculations for the relativistic closed-shell atoms with d and f orbitals, i.e., from zinc (Z=30) up to nobelium (Z=102), by using a universal Gaussian basis set generated previously by employing the generator coordinate Dirac–Fock method. The Dirac–Fock–Breit energy results presented in this work are the best, so far, obtained for the relativistic closed-shell atoms from Zn (Z=30) through No (Z=102) by using Gaussian-type functions, and show the efficacy of the generator coordinate Dirac–Fock method in performing accurate Dirac–Fock–Breit calculations.