Constructing accurate machine-learned potentials and performing highly efficient atomistic simulations to predict structural and thermal properties
This work provides efficient atomistic simulation tools for researchers studying Cu-based solid electrolytes, though it is incremental in applying existing machine learning methods to a specific compound.
The study tackled predicting structural and thermal properties of Cu7PS6 for thermoelectric applications by developing neuroevolution and moment tensor potentials, achieving a 41-fold computational speed increase with NEP while maintaining accuracy comparable to DFT.
The $\text{Cu}_7\text{P}\text{S}_6$ compound has garnered significant attention due to its potential in thermoelectric applications. In this study, we introduce a neuroevolution potential (NEP), trained on a dataset generated from ab initio molecular dynamics (AIMD) simulations, using the moment tensor potential (MTP) as a reference. The low root mean square errors (RMSEs) for total energy and atomic forces demonstrate the high accuracy and transferability of both the MTP and NEP. We further calculate the phonon density of states (DOS) and radial distribution function (RDF) using both machine learning potentials, comparing the results to density functional theory (DFT) calculations. While the MTP potential offers slightly higher accuracy, the NEP achieves a remarkable 41-fold increase in computational speed. These findings provide detailed microscopic insights into the dynamics and rapid Cu-ion diffusion, paving the way for future studies on Cu-based solid electrolytes and their applications in energy devices.