Symmetry-preserving random batch Ewald method for constant-potential simulation of electrochemical systems

Abstract: Constant potential molecular dynamics simulation plays important role for applications of electrochemical systems, yet the calculation of charge fluctuation on electrodes remains a computational bottleneck. We propose a highly scalable, symmetry-preserving random batch Ewald (SRBE) algorithm to address this challenge. The SRBE algorithm deterministically computes the low-frequency components along the direction perpendicular to electrodes, while efficiently approximating the remaining components using random batch sampling. This approach simultaneously reduces charge and force fluctuations while satisfying the symmetry-preserving mean field condition in anisotropic systems with large aspect ratios. Numerical experiments on electrode/ionic liquid systems validate the high accuracy of the SRBE method in capturing dynamic charging processes and equilibrium electric double layer structures. The SRBE method achieves parallel efficiency improvements of up to two orders of magnitude compared with conventional FFT-based algorithms. These findings highlight its strong potential for enabling large-scale electrochemical simulations and its broad applicability to practical problems in the field.