Density functional and neural-network potential simulations of Ag migration in disordered electrolytes
Phys. Rev. Materials 10, 085601 – Published 11 August, 2026
DOI: https://doi.org/10.1103/75rr-pqqp
Abstract
Density functional/molecular dynamics (DF/MD) simulations on with four compositions of silver provide valuable information on the structures and energetics of the amorphous material. Ag fills the available empty volume (cavities, voids) and interacts mainly with sulfur. The number of Ag-Ag contacts increases with increasing Ag composition, leading mainly to branched chains that partially disrupt the covalent Ge-S network. We use DF/MD simulations to study the energetics of Ag dissolution, the structures of alloys for differing Ag content, migration paths in the energy surfaces at 0 K, and liquid dynamics at 1100 K, close to the experimental melting point. We discuss the electronic structures of the optimized glass structures. DF/MD simulations can describe the dynamics of these systems at liquid temperatures, but are too short to allow the study of Ag migration at lower temperatures. We have used DF/MD trajectories and generated snapshots of high- liquids to develop a neural network potential (NNP) that allows simulations of these systems for tens of nanoseconds. These simulations are used for migration dynamics at , leading to a linear behavior of the mean-square displacement on a logarithmic scale; the effective migration energy of Ag (, with little composition dependence) agrees well with the static DF migration barriers.
