A STUDY OF SULFUR-CONTAINING MOLECULES USING HARTREE-FOCK, MP2 AND DFT (HYBRID) METHODOLOGIES

The performance is examined of the B3P86 hybrid exchange-correlation f unction for a set of 21 sulphur-containing molecules. Optimized geomet ries, harmonic frequencies and mean molecular polarizabilities are pre sented, and compared with calculations to the Hartree-Fock and MP2 lev els of theory, and with appropriate experimental results. The hybrid f unctional predicts geometries at a level comparable with the MP2 resul ts; harmonic frequencies are in closer agreement with experimental res ults than either MP2 or Hartree-Fock method; mean molecular polarizabi lities predicted by the hybrid functional appear to be substantially c loser to experiment than those calculated by either of the other two m ethods.