A silicalite-1/water potential function was developed using quantum chemical calculations at the Hartree-Fock level. The silicalite-1 crystal structure was represented by three fragments in which the chemical compositions were O10Si10H20, O30Si22H44 and O35Si29H58. Ab initio calculations were performed for 1032 fragment-water configurations where water coordinates were generated within the fragments. The intermolecular silicalite-1/water potentials developed from those data points were then used in molecular dynamics simulations. The diffusion coefficients obtained at 298 and 393K, 3.3 x 10-9 and 6.7 x 10-9m2/s respectively, were in agreement with pulsed field gradient nuclear magnetic resonance measurements.

Ab initio Potential Energy Surface and Molecular Dynamics Simulations for the Determination of the Diffusion Coefficient of Water in Silicalite-1. C.Bussai, S.Hannongbua, S.Fritzsche, R.Haberlandt: Chemical Physics Letters, 2002, 354[3-4], 310-5. See also: Studies in Surface Science and Catalysis, 2002, 142B, 1979-86