Towards the solution of the many-electron problem in real materials: equation of state of the hydrogen chain with state-of-the-art many-body methods

TL;DR

This paper provides a comprehensive benchmark of modern many-body computational methods for determining the equation of state of an infinite hydrogen chain, addressing key limits and validating results with high accuracy.

Contribution

It systematically compares various many-body methods for the hydrogen chain, establishing benchmarks and analyzing approaches to the continuous and thermodynamic limits.

Findings

Accurate ground-state energy per atom across bond lengths.

Validated methods for reaching the continuous space and thermodynamic limits.

Provided benchmark data for future method development.

Abstract

We present numerical results for the equation of state of an infinite chain of hydrogen atoms. A variety of modern many-body methods are employed, with exhaustive cross-checks and validation. Approaches for reaching the continuous space limit and the thermodynamic limit are investigated, proposed, and tested. The detailed comparisons provide a benchmark for assessing the current state of the art in many-body computation, and for the development of new methods. The ground-state energy per atom in the linear chain is accurately determined versus bondlength, with a confidence bound given on all uncertainties.