The nuclear spin-rotation constants of HCY, HSiY, and SiY2 (Y=F, Cl). An ab initio study.

The nuclear-spin-rotation constants of fluoro- HCF and chloro- HCCl carbene, of the corresponding silylenes HSiF and HSiCl, and of difluoro- and dichlorosilylene SiF2 and SiCl2 are quantum-chemically investigated employing the coupled-cluster singles and doubles model augmented by a perturbative treatment of triple excitations together with various sequences of correlation-consistent basis sets. Theoretical best estimates are obtained through consideration of corrections for core correlation and of zero-point vibrational contributions. In addition, nuclear quadrupole coupling constants for the chlorine containing species are determined. A thorough comparison with experiment is made.