The fundamental vibrational frequencies of the silyl anion (SiH- 3)

Ab initio quantum mechanical methods have been used to predict the vibrational frequencies for the silyl anion (SiH 3 - , C 3v ). In the present study, the self-consistent field, the configuration interaction with single and double excitations, and the coupled cluster with single and double excitations wavefunctions were used in conjunction with the triple zeta plus double polarization plus diffuse function basis set. Anharmonicity has been explicitly considered using vibrational perturbation theory. The effects of diffuse s functions on the hydrogen atoms are found to be surprisingly large