Relativistic coupled-cluster calculation of core ionization potentials using the normal and the semi-normal ordered ansatz

Abstract

In this paper we have applied the cluster-expansion ansatz for the wave operator Ω which incorporates the orbital relaxation and correlation effects in an efficient manner. We have used both ordinary and normal ordered cluster operator (Ω) to compute the ionization potential for different states of Ne, Ar and Kr. The result of our calculation clearly shows how the relaxation and correlation effects play a role in determining the ionization potential, one of the interesting aspects of theoretical spectroscopy.