Poisson's ratio in cryocrystals under pressure

TL;DR

This study investigates how Poisson's ratio in cryocrystals like solid hydrogen and rare gases changes under pressure, revealing diverse monotonic and non-monotonic behaviors through advanced computational methods.

Contribution

It provides a comparative analysis of Poisson's ratio under pressure for various cryocrystals using both semi-empirical and first-principles calculations, highlighting different pressure dependencies.

Findings

Helium's PR decreases monotonically with pressure.

Ar, Kr, Xe PR increases monotonically with pressure.

Hydrogen and Ne exhibit non-monotonic PR behavior with deep minima.

Abstract

We present results of lattice dynamics calculations of Poisson's ratio (PR) for solid hydrogen and rare gas solids (He, Ne, Ar, Kr and Xe) under pressure. Using two complementary approaches - the semi-empirical many-body calculations and the first-principle density-functional theory calculations we found three different types of pressure dependencies of PR. While for solid helium PR monotonically decreases with rising pressure, for Ar, Kr, and Xe it monotonically increases with pressure. For solid hydrogen and Ne the pressure dependencies of PR are non-monotonic displaying rather deep minimums. The role of the intermolecular potentials in this diversity of patterns is discussed.