Correlation and relativistic effects are both needed for accurate atomic structure calculations of energy levels and their atomic properties. For transition probabilities between low-lying levels of a spectrum, accurate wave functions for the outer region of the atom or ion are required. For lighter systems, relativistic effects can be included through the Breit-Pauli approximation.This paper outlines the advances in the treatment of correlation and describes the current state of Breit-Pauli calculations for complex systems.
Journal of Physics
atomic structure, correlation, energy levels, relativistic effects, transition probabilities, wave function expansions