Ab initio generalized valence force field for zeolite modelling. 1. Siliceous zeolites Original Research Article

A new potential permitting the molecular dynamics study of the structural and dynamical properties of siliceous zeolites is presented and tested. It is based on a quantum-chemical derivation of the Cartesian force constants which are transformed into an internal coordinate system and corrected for systematic errors. The calculated vibrational spectra for three siliceous zeolites (sodalite, faujasite and silicalite) show a very satisfactory agreement with the experimental ones and the force field is very similar to a potential recently derived from experimental data.