Parallel kinetic Monte Carlo simulation framework incorporating accurate models of adsorbate lateral interactions

Area of Science:

• Surface science and heterogeneous catalysis.
• Computational chemistry and materials science.
• Chemical kinetics and reaction dynamics.

Background:

• Ab initio kinetic Monte Carlo (KMC) simulations are vital for understanding catalytic processes.
• Accurate simulations depend on detailed knowledge of reaction kinetics and adsorbate energetics.
• Previous KMC models often simplified adsorbate interactions, limiting predictive accuracy.

Purpose of the Study:

• To develop a general-purpose KMC package, Zacros, that incorporates detailed cluster expansion models for adlayer energetics.
• To address the computational cost associated with long-range interactions through parallelization.
• To improve the accuracy of catalytic rate predictions by including many-body and long-range terms.

Main Methods:

• Development of Zacros, a FORTRAN2003 KMC package based on a graph-theoretical framework.
• Implementation of parallelization using OpenMP to manage computational expense.
• Benchmarking the framework using a NO oxidation system, comparing results with and without long-range interactions.

Main Results:

• The developed Zacros package enables KMC simulations with detailed cluster expansion models.
• Parallelization with OpenMP effectively reduces computational time for complex systems.
• Simulations demonstrate that first nearest-neighbor interactions alone can lead to significant errors in catalytic rate prediction.

Conclusions:

• Accurate prediction of catalytic rates necessitates the inclusion of long-range interactions within cluster expansion models.
• The Zacros package provides a robust and efficient tool for advanced KMC simulations in catalysis.
• The study highlights the importance of detailed energetic modeling for reliable computational catalysis.