Breit interaction in multi-configuration relativistic atomic calculations

Abstract

The Breit interaction which gives the leading correction to the Coulomb potential in quantum electrodynamics, is required for precision calculations of binding energies of inner electrons in heavy atoms for calculations of multiplet structure, and for other applications. The correct form for use in multi-configuration calculations is discussed, and the angular momentum reduction to a sum of radial integrals is carried out completely in an approximation valid for all problems except those involving very tightly bound electrons. The coefficients are presented in a form suitable for computation; a computer program for matrix elements of the Breit interaction for general atomic states is at present under test.