Quasi-two-dimensional metallic hydrogen inside di-phosphide at high pressure

TL;DR

This paper models the structural and electronic properties of phosphorus hydrides, revealing that di-phosphine can form a quasi-two-dimensional metallic hydrogen lattice stabilized by phosphorus under high pressure.

Contribution

It introduces a mathematical modeling approach to predict the formation of 2D metallic hydrogen in phosphorus hydrides, a novel insight into high-pressure phases.

Findings

Di-phosphine can form a stable 2D metallic hydrogen lattice.

The structure is metastable with respect to phonon spectrum analysis.

Comparison with sulfur hydrides highlights similarities in high-pressure behavior.

Abstract

The method of mathematical modeling was used for the calculation of the structural, electronic, phonon, and other characteristics of various normal phases of phosphorus hydrides with stoichiometry PHk. It was shown that the di-phosphine may form 2D lattice of the metallic hydrogen, stabilized by phosphorus atoms under high hydrostatic compressive pressure. The resulting structure with the elements of H-P-H is a locally stable one in the phonon spectrum (or metastable). The properties of di-phosphine with the properties of similar structures such as thesulphur hydrides were compared.