Investigation of dependence of electronic mass on its velocity in atoms using Breit-Pauli approximation

In this study, Hmv =-(1/8me3c2)p4 operator which is a relativistic correction term for kinetic energy in Quasirelativistic theory has been analyzed. Using perturbation theory, the nonrelativistic wave equation, involving relativistic mass correction term which is proportional with a2 suggested by Breit, has been considered. In this equation, using noninteger n-Slater type functions, matrix elements have been found for atomic Hartree-Fock-Roothan equations.The origin of relativistic mass correction term has been analyzed obtaining the series expansion of Einstein?s relativistic energy expression in power of a2. Matrix elements of the first 8 terms which are obtained from series expansion have been calculated analytically. These analytical expressions have been analyzed for different values of quantum numbers.