AB-INITIO INFRARED AND RAMAN-SPECTRA OF THE H3SIO4- MONOMERIC ANIONICSPECIES

Spectroscopic parameters for the stable minimum-energy structures on t he potential energy surface for the H3SiO4- monomeric silicate species are reported. Harmonic frequencies and infrared and Raman intensities of the vibrational normal modes are analytically calculated at the ab initio Hartree-Fock level. Calculations were carried out with the 6-3 1G basis set and also including diffuse functions (3-21++G and 3-21+G* basis sets) in order to assess their importance for the prediction of the vibrational spectrum of this anionic species. Comparisons with available experimental data are made.