Monte Carlo methods in Materials Studio

Abstract

We survey the use of the Monte Carlo method within the Materials Studio application, which integrates a large number of modules for molecular simulation. Several of these modules work by generating configurations of a system at random, which can then be used to calculate averages of interest – for instance, interaction energies of contacting pairs of molecules (Blends module) and properties of a flexible polymer chain (Conformers). A different technique is used to sample an appropriate physical distribution (which in practice is that for the canonical ensemble) using the Metropolis or configurational bias method. This is done by the Sorption module (which calculates the thermodynamic properties of small molecules in a matrix) and Amorphous Cell (which constructs periodic simulation cells). Lastly, certain other modules use simulated annealing and related methods to optimise a function, with application to crystal structure prediction from molecular structure (Polymorph Predictor), to crystal structure prediction from X-ray powder diffraction data (Powder Solve) and to find preferential sites for adsorption (Adsorption Locator).

Keywords::

• Monte Carlo
• Materials Studio
• simulated annealing
• Sorption
• morphology