Relativistic corrections to the hamiltonian for one and two electron atoms

Abstract

Relativistic corrections to the non-relativistic hamiltonian for one and two electron atoms are obtained by performing a Foldy-Wouthuysen transformation on the Dirac hamiltonian for two particles in a field of electromagnetic radiation. To order mc ² α⁴ the reduced hamiltonian is identical to that obtained from quantum electrodynamics and in better agreement with experiment than that obtained from the Breit hamiltonian. The reduced hamiltonian can also be used to obtain transition operators and these also agree with previous work.