Interatomic potential for germanium dioxide empirically fitted to an ab initio energy surface

We have developed a two-body potential for GeO2 which we employ for modeling the cr-quartz and the rutilelike phases of GeO2. In simulations both at ambient and at elevated pressure, the bond angles and bond lengths agree well with experimental values. The vibrational spectra have been analyzed both from the harmonic approximation and from velocity autocorrelation functions. The limits of the harmonic approximation are demonstrated with a method called selective molecular-dynamics simulation. The alpha- to beta-quartz phase transition is successfully modeled. [S0163-1829(98)03542-5].