The Rotational g Tensor of HF, H2O, NH3, and CH4: A Comparison of Correlated Ab Initio Methods

Abstract

Abstract The rotational g tensors of hydrogen fluoride, water, ammonia and methane are calculated at their equilibrium geometries with various correlated ab initio methods. Among the methods employed are the second order polarization propagator approximation (SOPPA), which was developed by Jens Oddershede and co-workers, the second order polarization propagator approximation with coupled cluster singles and doubles amplitudes (SOPPA(CCSD)), Moller–Plesset perturbation theory in second (MP2), third (MP3) and fourth order (MP4), the coupled cluster method (CCSD) and finally the multiconfigurational self-consistent field method (MCSCF) in the form of complete (CASSCF) and restricted active space (RASSCF) variant with several different active spaces. The results of calculations with the different methods using two large conventional basis sets are compared.