Amorphous silicon structures generated using a moment tensor potential and the activation relaxation technique nouveau
Phys. Rev. B 111, 214209 – Published 23 June, 2025
DOI: https://doi.org/10.1103/w12r-gwzb
Abstract
Preparing realistic atom-scale models of amorphous silicon (a-Si) is a decades-old condensed-matter physics challenge. Herein, we combine the activation relaxation technique nouveau (ARTn) to a moment tensor potential (MTP) to generate seven a-Si models containing between 216 and 4096 atoms. A thorough analysis of their short-range and medium-range structural properties is performed, alongside assessments of excess energy and mechanical properties. The seven ARTn-MTP models are compared with available experimental data and other high-quality a-Si models present in the literature. The seven ARTn-MTP a-Si models are in excellent agreement with available experimental data. Notably, several of our models, including the 216-atom, 512-atom, and 1000-atom a-Si models, exhibit low coordination defects without any traces of crystalline grains. Historically overlooked in previous research, our study underlines the need to assess the validity of the continuous random-network hypothesis for the description of perfect amorphous model by characterizing local crystalline environment and to explore the crystallization process of a-Si through modeling.
