Structural and electronic properties of solid molecular hydrogen from many-electron theories

TL;DR

This study uses advanced many-electron theories to accurately model the structural and electronic properties of solid hydrogen phase III, aligning well with experimental data and addressing previous discrepancies in metallization pressure estimates.

Contribution

The paper introduces optimized atomic structures of solid hydrogen phase III using second-order perturbation theory, improving upon previous density functional approaches.

Findings

Optimized structures show more accurate H2 bond lengths.

Calculated band gaps and vibrational frequencies match experimental data.

Results help clarify discrepancies in metallization pressure estimates.

Abstract

We study the structural and electronic properties of phase III of solid hydrogen using accurate many-electron theories and compare to state-of-the-art experimental findings. The atomic structures of phase III modelled by C2/c-24 crystals are fully optimized on the level of second-order perturbation theory, demonstrating that previously employed structures optimized on the level of approximate density functionals exhibit errors in the H$_2$ bond lengths that cause significant discrepancies in the computed quasi particle band gaps and vibrational frequencies compared to experiment. Using the newly optimized atomic structures, we study the band gap closure and change in vibrational frequencies as a function of pressure. Our findings are in good agreement with recent experimental observations and may prove useful in resolving long-standing discrepancies between experimental estimates of metallization pressures possibly caused by disagreeing pressure calibrations.