Simulation of crystalline silica structures based on a potential with a many-body term

A Monte Carlo technique based on the Metropolis approach has been employed to simulate the energy and structure-related properties of systems containing Si and O atoms. The method uses a semi-empirical potential function comprising two- and three-body interactions. The potential does not utilise any covalency or ionicity concept nor does it categorise the interactions between particles into short or long range. The only many-body term considered to be significant is that due to the long-range triple-dipole interaction. Calculated results for energetics and structural properties of four different allotropic forms of SiO 2 (for crystalline bulk) agree well with experimental data within acceptable limits. In addition, simulations were performed to estimate the properties for the (001) surface of low-cristobalite. The importance of three-body interactions on the structural stability of SiO 2 phases is also discussed.