Extended Coupled Cluster Approach for Molecular Properties: Study of H2O and HF Complexes

Abstract: In this paper, we study stationary variant of extended coupled-cluster response approach for properties. This has been studied at the singles and doubles approximation using cubic-truncated functional. This approximation has been studied earlier around equilibrium for small molecules. In this paper, efficacy of this approximation has been shown using perturbative arguments. Further we have calculated dipole moments and polarizabilities of weakly interacting dimers of HF, H2O and H2O - HF complex. Results of HF and H2O monomers have been presented at the same level for comparison. The results have been compared with experimental results, wherever available and other theoretical results