Vitriflow: calibrated amorphous structure ensembles from melt-quench simulation

Abstract

Melt--quench molecular dynamics is widely used to construct amorphous materials models, but the resulting ensemble is defined by choices that are often made implicitly: numerical settings, melt temperature, liquid-hold time, quench rate, system size, and post-generation screening. We introduce vitriflow, a computational materials methodology that turns these choices into an explicit decision chain. The framework couples numerical stability, descriptor-based protocol calibration, user-defined artefact screening, and statistical convergence of the generated analysis ensemble in a material-specific descriptor space. We demonstrate the approach for a-SiO$_2$, a-Si$_3$N$_4$, and a-Sm$_2$O$_3$, which respectively test tetrahedral network fidelity, MG2 $\rightarrow$ PBE $\rightarrow$ HSE06 DFT refinement of a heteropolar nitride, and amorphous/crystal discrimination in a mixed-coordination rare-earth oxide. vitriflow separates defect-free from oxygen-bridge-defective silica, quantifies DFT-refinement response in a common a-Si$_3$N$_4$ structural population, and removes recrystallised Sm$_2$O$_3$ structures without imposing fixed coordination. The result is a reproducible route for generating amorphous ensembles whose numerical settings, thermal protocol, screening actions, and statistical precision are selected from the materials question rather than assumed a priori.