Franck–Condon profiles in photodetachment-photoelectron spectra of and based on vibrational configuration interaction wavefunctions

Abstract

Explicitly electron correlating coupled cluster calculations, CCSD(T)-F12a, were performed to determine three-dimensional potential energy hypersurfaces of disulphanide and disulphanyl in an automated approach. Surfaces for different electronic states were used in a Watson rovibrational Hamiltonian ansatz to obtain the correlated anharmonic vibrational wavefunctions. Subsequently the anharmonic Franck–Condon overlap integrals were evaluated. The computed Franck–Condon profiles were compared to experimental photodetachment-photoelectron spectra and confirm essentially the assignments made previously. The profiles indicate, however, additional weaker, and as of yet unresolved, additional features.