Zacros is a Kinetic Monte Carlo (KMC) software package written in Fortran, for simulating molecular phenomena on catalytic surfaces. For an introduction to KMC, you may enjoy reading "What's KMC All About and Why Bother"! Zacros enables researchers in the areas of Computational Catalysis and Surface Science to perform dynamic modelling of adsorption, desorption, surface diffusion, and reaction processes on heterogeneous catalysts. The rates of these elementary processes are typically computed from ab initio simulations, thereby enabling the prediction of catalytic performance metrics (such as activity and selectivity) from first principles. The software can also perform simulations of temperature programmed desorption/reaction spectra, enabling Surface Scientists to validate in detail hypothesised kinetic mechanisms against experimental data.
The software implements the Graph-Theoretical KMC methodology coupled with cluster expansion Hamiltonians for the adlayer energetics and Brønsted-Evans-Polanyi relations for the activation energies of elementary events. This framework can naturally capture:
- Steric exclusion effects for species that bind in more than one catalytic sites.
- Complex reaction patterns involving adsorbates in specific binding configurations and neighbouring arrangements.
- Spatial correlations and ordering arising from adsorbate lateral interactions that involve many-body contributions.
- Changes in the activation energies of elementary events, influenced by the energetic interactions of reactants with neighbouring spectator species.
As of version 3.01, Zacros incorporates an MPI implementation of the Time-Warp algorithm for distributed (and exact) KMC simulations, making it possible to harness the computational power of massively parallel computing architectures.
Zacros is developed by a team of scientists at University College London (UCL), led by Dr Michail Stamatakis, and is distributed by UCL Business (UCLB), the commercialisation company of University College London. It has already been used in several publications by the originating group and beyond, unravelling complex catalytic phenomena. Give Zacros a try if you are a DFT expert investigating catalytic pathways and looking for a tool to perform kinetic modelling, or an experimentalist in the Surface Science or Catalysis fields, seeking to validate hypothesised kinetic mechanisms against experiments.