Realistic models of amorphous silica: A comparative study of different potentials

The creation of realistic models of amorphous silica has been studied using the Monte Carlo based method of Wooten, Winer, and Weaire, where the bond-topology is optimized with respect to an interatomic potential model. The commonly used Keating potentials are compared and their strengths and weaknesses are assessed. The mean oxygen bond-angle obtained using these potentials turned out to be too small. A modification of the potential parameters is shown to correct this feature and thus produce better results when used with the Wooten-Winer-Weaire method.