Molecular applications of open-shell coupled cluster theory for energy difference calculations: ionization and auger spectra of F₂

Abstract

The first ab initio molecular applications of our open-shell coupled cluster (CC) method for direct calculation of energy differences are reported. Starting from the zero-valence ground-state problem, various one-, two-, ··· m-valence problems are hierarchically generated. Ionization and Auger spectrum calculations for F₂ illustrate typical one- and two-valence situations. Particular attention is paid to generate alternative solutions corresponding to satellite peaks in the IP by exploiting the non-linear nature of the CC equations. The results are encouraging.