Towards a density functional description of liquid pH2

TL;DR

This paper develops and tests finite-temperature density functionals to accurately model the surface and bulk properties of liquid parahydrogen, including surface tension, wetting, and cavitation phenomena.

Contribution

It introduces two novel density functionals—zero-range and finite-range—for liquid pH2, improving the description of surface and bulk properties at finite temperature.

Findings

Finite-range functional reproduces experimental surface properties.

Surface tension at low temperature is accurately modeled.

Wetting transition and cavitation behaviors are effectively captured.

Abstract

A finite-temperature density functional approach to describe the properties of parahydrogen in the liquid-vapor coexistence region is presented. The first proposed functional is zero-range, where the density-gradient term is adjusted so as to reproduce the surface tension of the liquid-vapor interface at low temperature. The second functional is finite-range and, while it is fitted to reproduce bulk pH2 properties only, it is shown to yield surface properties in good agreement with experiments. These functionals are used to study the surface thickness of the liquid-vapor interface, the wetting transition of parahydrogen on a planar Rb model surface, and homogeneous cavitation in bulk liquid pH2.