Molecular simulation of chemical reaction equilibria by Kinetic Monte Carlo

ABSTRACT

We describe a new algorithm for the molecular simulation of chemical reaction equilibria, which we call the Reactive Kinetic Monte Carlo (ReKMC) algorithm. It is based on the use of the equilibrium Kinetic Monte Carlo (eKMC) method (Ustinov et al., J. Colloid Interface Sci., 2012, 366, 216–223) to generate configurations in the underlying nonreacting system and to calculate the species chemical potentials at essentially zero marginal computational cost. We consider in detail the typical case of specified temperature, T and pressure, P, but extensions to other thermodynamic constraints are straightforward in principle. In the course of this work, we also demonstrate an alternative method for calculating simulation box volume changes in NPT ensemble simulations to achieve the specified P. We consider two sets of example reacting systems previously considered in the literature, and compare the ReKMC results and computational efficiencies with those of different implementations of the REMC algorithm (Turner et al., Molec. Simulation, 2008, 34, 119–146).

GRAPHICAL ABSTRACT

KEYWORDS:

• Chemical reaction equilibrium
• molecular simulation
• Kinetic Monte Carlo
• chemical potential

Acknowledgements

The computing facilities provided by SHARCNET (www.sharcnet.ca) and Compute Canada (www.computecanada.ca) are also gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Braden Kelly http://orcid.org/0000-0003-3708-6517

William R. Smith http://orcid.org/0000-0002-1982-2050

Additional information

Funding

This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) under grant number STPGP 479466-15.