Diffusion Monte Carlo study of the equation of state of solid ortho-D$_2$

TL;DR

This study uses Diffusion Monte Carlo simulations to evaluate the equation of state of solid ortho-D₂ under various pressures, comparing two potentials with experimental data to validate their accuracy.

Contribution

It demonstrates that the Silvera-Goldman potential accurately models solid ortho-D₂, effectively incorporating three-body effects through an effective two-body potential.

Findings

Silvera-Goldman potential aligns well with experimental data

Three-body forces can be modeled effectively with two-body potentials in solid ortho-D₂

Pressure range studied up to 350 MPa

Abstract

We present results of Diffusion Monte Carlo calculations for a system of solid ortho-D_2 at different densities, for pressure ranging from 0 up to 350MPa. We compare the equation of state obtained using two of the most used effective intermolecular potentials, i.e. the Silvera--Goldman and the Buck potentials, with experimental data, in order to assess the validity of the model interactions. The Silvera-Goldman potential has been found to provide a satisfactory agreement with experimental results, showing that, as opposed to what recently found for p-H_2, three--body forces can be efficiently accounted for by an effective two--body term.