Redesigning OpenKMC for Multi-Component Trillion-Atom Simulations on the New Sunway Supercomputer

Abstract

The atomic kinetic Monte Carlo method plays an important role in material simulations by connecting the microscale mechanism with macroscale evolution. However, the long-time simulation of multi-component materials is highly challenging because it demands significant computing resources. With the advent of exascale computing, ultra-high computing power can enable kinetic Monte Carlo (KMC) simulations. In this paper, we deeply optimize OpenKMC for the new-generation Sunway supercomputer. This includes optimizing the memory access for the SW39000 architecture, eliminating various redundant computations at growing scales, and proposing a communication strategy for heterogeneous platforms. In addition, we expanded OpenKMC's simulation for multi-component alloys. Finally, the acceleration framework can produces a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$37\times$</tex-math></inline-formula> performance enhancement on the Sunway platform. Furthermore, when powered by 10 million cores, our program can perform trillion-atom simulations of complex multi-component alloys with 85% parallel efficiency.