Reverse Monte Carlo modelling

Abstract

Reverse Monte Carlo (RMC) modelling is a general method of structural modelling based on experimental data. RMC modelling can be applied to many different sorts of data, simultaneously if wished. Powder and single-crystal neutron diffraction (including isotopic substitution), x-ray diffraction (including anomalous scattering) and electron diffraction, extended x-ray absorption fine structure and nuclear magnetic resonance (magic angle spinning and second moment) have already been used to provide data. RMC modelling can also be applied to many different types of system-liquids, glasses, polymers, crystals and magnetic materials. This article outlines the RMC method and discusses some of the common misconceptions about it. It is stressed that RMC models are neither unique nor 'correct'. However, they are often useful for aiding our understanding either of the structure itself, or of the relationships between local structure and other physical properties. Examples are given and the possibilities for further development of the RMC method are discussed.

Reverse Monte Carlo simulations and Raman scattering of an amorphous GeSe4 alloy produced by mechanical alloying

“…The basic idea and the algorithm of the standard RMC method are described elsewhere 23,24,25,26 and its application to different materials is reported in the literature 29,30,31,32,33,34,35,36,37,38,39,40,41 . In the RMC procedure, a threedimensional arrangement of atoms with the same density and chemical composition of the alloy is placed into a cell (usually cubic) with periodic boundary conditions and the G RMC ij (r) functions corresponding to it are directly calculated through…”

“…In this paper, we investigated the SRO and IRO of an amorphous GeSe 4 alloy produced by MA (MA-a-GeSe 4 ) starting from the elemental powders of Ge and Se using Raman spectroscopy (RS), X-ray diffraction and reverse Monte Carlo (RMC) simulations 23,24,25,26 of its XRD S(K). We were interested in studying two main points.…”

Inverse simulated annealing: Improvements and application to amorphous InSb

“…While this allows for an efficient and routine modeling of rather complex disordered structures, the resulting models are not necessarily physical sensible. Furthermore, since no information on the potential energy surface is exploited, a variety of different structural models that are very different from each other, but in similarly good agreement with experiment, can be generated [6][7][8][9][10][11][12][13] . Finite temperature Molecular Dynamics (MD) or Monte Carlo (MC) simulations offer an alternative route to generate glassy models by quenching from the melt using the simulated annealing (SA) algorithm 14 .…”

Structural investigation of gallate glass using L3-edge extended X-ray absorption spectroscopy and computer simulation

“…To the best of our knowledge, several techniques such as Reverse Monte Carlo (RMC) [9] and Empirical Potential Structural Refinement (EPSR) [10] have been recently developed to obtain structural models of glasses from diffraction data. An alternative approach to the gallate glasses is to use Molecular Dynamics (MD) simulation techniques [11,12] to produce distribution function or diffraction patterns that can be compared directly with the experimental data.…”