Towards efficient and accurate \emph{ab initio} solutions to periodic systems via transcorrelation and coupled cluster theory

TL;DR

This paper introduces a combined transcorrelation and coupled cluster approach that accelerates basis set convergence and extends applicability to strongly correlated systems, achieving high accuracy in the uniform electron gas.

Contribution

The paper presents a novel combination of transcorrelation and coupled cluster methods that improves efficiency and accuracy for strongly correlated periodic systems.

Findings

Achieves ground state energies with errors ≤ 0.001 a.u./electron compared to quantum Monte Carlo.

Significantly improves convergence rate with respect to basis set size.

Extends applicability of coupled cluster methods to strongly correlated regimes.

Abstract

We propose a streamlined combination scheme of the transcorrelation (TC) and coupled cluster (CC) theory, which not only increases the convergence rate with respect to the basis set, but also extends the applicability of the lowest order CC approximations to strongly correlated regimes in the three dimensional uniform electron gas (3D UEG). With the correct physical insights built into the correlator used in TC, highly accurate ground state energies with errors $\leq 0.001 $ a.u./electron relative to the state-of-the-art quantum Monte Carlo results can be obtained across a wide range of densities. The greatly improved efficiency and accuracy of our methods hold great promise for strongly correlated solids where many other methods fail.