Stable solid molecular hydrogen above 900K from a machine-learned potential trained with diffusion Quantum Monte Carlo
Materials Science
2023-02-22 v2 Computational Physics
Abstract
We survey the phase diagram of high-pressure molecular hydrogen with path integral molecular dynamics using a machine-learned interatomic potential trained with Quantum Monte Carlo forces and energies. Besides the HCP and C2/c-24 phases, we find two new stable phases both with molecular centers in the Fmmm-4 structure, separated by a molecular orientation transition with temperature. The high temperature isotropic Fmmm-4 phase has a reentrant melting line with a maximum at higher temperature (1450K at 150GPa) than previously estimated and crosses the liquid-liquid transition line around 1200K and 200GPa.
Cite
@article{arxiv.2209.00658,
title = {Stable solid molecular hydrogen above 900K from a machine-learned potential trained with diffusion Quantum Monte Carlo},
author = {Hongwei Niu and Yubo Yang and Scott Jensen and Markus Holzmann and Carlo Pierleoni and David M. Ceperley},
journal= {arXiv preprint arXiv:2209.00658},
year = {2023}
}
Comments
4 pages, 4 figures, updated acknowledgment