Refining disordered structural models using reverse monte carlo methods: Application to vitreous silica

Abstract

The Reverse Monte Carlo (RMC) modelling technique produces a structural model which is only constrained to agree with the available experimental data. For simple disordered systems good, unbiased structural descriptions are produced in this way. However, in general, a good fit to the data is merely a necessary, not a sufficient criterion for a good structural model and with more complex systems, RMC models are unlikely to be physically sensible. RMC methods can, however, still be used to yield good disordered structures if used in a suitably constrained manner. This paper describes the RMC technique and how it can be used to refine disordered structures. Reference is made throughout to various proposed models of vitreous silica.

Key Words:

• RMC computer modeling
• Structural disorder
• Silica