title: Towards a spin-adapted coupled-cluster theory for high-spin open-shell states.
abstract: A spin-adapted coupled-cluster (SA-CC) scheme based on the additional consideration of spin constraints is proposed for the quantum chemical treatment of high-spin open-shell cases. Its computational feasibility is demonstrated via a pilot implementation within the singles and doubles approximation. Test calculations indicate that the suggested SA-CC scheme provides results of similar accuracy as the more traditional schemes without spin adaptation.
authors.affiliation: Institut für Physikalische Chemie, Universität Mainz, D-55099 Mainz, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Heckert
authors.forename: Oliver
authors.initials: O
authors.lastname: Heun
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gauss
authors.forename: Péter G
authors.initials: PG
authors.lastname: Szalay