Ab initio Monte Carlo simulations for finite-temperature properties: Application to lithium clusters and bulk liquid lithium

TL;DR

This paper demonstrates that ab initio Monte Carlo simulations can accurately determine the finite-temperature properties of lithium systems, offering a computationally efficient alternative to molecular dynamics.

Contribution

It introduces a method combining ab initio calculations with Monte Carlo simulations to study finite-temperature properties of lithium clusters and bulk liquid lithium.

Findings

Structural properties agree with experimental data

Method is computationally comparable to molecular dynamics

Feasible for large condensed-matter systems at nonzero temperatures

Abstract

Ab initio Monte Carlo simulations have been performed to determine the equilibrium properties of liquid lithium and lithium clusters at different temperatures. First-principles density-functional methods were employed to calculate the potential-energy change for each proposed change of configuration, which was then accepted or rejected according to the Metropolis Monte Carlo scheme. The resulting structural properties are compared to data from experimental measurements and ab initio molecular dynamics simulations. It is shown that accurate structural information can be obtained with ab initio Monte Carlo simulations at computational costs comparable to ab initio molecular dynamics methods. We demonstrate that ab initio Monte Carlo simulations for the properties of fairly large condensed-matter systems at nonzero temperatures are feasible.