The Breit-Brown operator of the atomic Kramers equation

Abstract

The energy-dependent 'Breit-Brown' operator is constructed from a recently derived 'Kramers-Coulomb' equation. The resulting equation is equivalent to the usual Dirac-Breit equation, despite its very different appearance. Spin effects are separated covariantly from spinless relativistic effects. Nuclear recoil is included.

Transformation of Breit operators into hyperfine-like operators

“…The main step in the derivation of ( 2) from ( 7) was performed in 1990 for the special case of two-electron atoms [7]. One defines an operator Z which satisfies…”