Ab initio path integral Monte Carlo simulations of the uniform electron gas on large length scales

TL;DR

This paper advances the simulation of the warm dense electron gas by employing a novel PIMC technique that enables large-scale, accurate, ab initio calculations of fermionic systems without exponential computational costs.

Contribution

It introduces a new PIMC approach for fermionic systems that allows simulations of up to 1000 particles, overcoming previous size limitations.

Findings

Accurate static structure factor across all length scales.

Reliable static density response function results.

Effective local field correction calculations.

Abstract

The accurate description of non-ideal quantum many-body systems is of prime importance for a host of applications within physics, quantum chemistry, material science, and related disciplines. At finite temperatures, the gold standard is given by \textit{ab initio} path integral Monte Carlo (PIMC) simulations, which do not require any empirical input, but exhibit an exponential increase in the required compute time for fermionic systems with increasing the system size $N$. Very recently, it has been suggested to compute fermionic properties without this bottleneck based on PIMC simulations of fictitious identical particles. In the present work, we use this technique to carry out very large ($N\leq1000$) PIMC simulations of the warm dense electron gas and demonstrate that it is capable of providing a highly accurate description of investigated properties, i.e., the static structure factor, the static density response function, and local field correction, over the entire range of length scales.