Multi-reference coupled-cluster study of the potential energy surfaceof the hydrogen fluoride dissociation including excited states

摘要

Multi-reference coupled-cluster calculations for the potential energy surface of the HF molecule includ-ing excited states are carried out. Using the multi-reference exponential wavefunction [M. Hanrath, J.Chem. Phys. 123 (2005) 84102] and the single-reference formalism based multi-reference coupled-clus-ter ansatz [J. Chem. Phys. 94 (1991) 1229, J. Chem. Phys. 99 (1993) 1875] the results are analyzed anddiscussed with respect to full Cl results. The present work completes previous studies which consideredcalculations with partially restricted residual equations only. A certain attention is paid to spatial degen-eracy issues.