Analytical evaluation of ground state gradients in quantum electrodynamics coupled cluster theory

TL;DR

This paper derives analytical gradients for quantum electrodynamics coupled cluster theory, enabling accurate molecular geometry optimization under strong light-matter coupling, with an efficient implementation and demonstration of cavity effects.

Contribution

It introduces the first derivation of ground state analytical gradients in QED coupled cluster theory and provides a Cholesky-based implementation for practical use.

Findings

Efficient implementation with performance timings

Optimized geometries showing cavity-induced effects

Validation of gradients in strong coupling regimes

Abstract

Analytical gradients of potential energy surfaces play a central role in quantum chemistry, allowing for molecular geometry optimizations and molecular dynamics simulations. In strong coupling conditions, potential energy surfaces can account for strong interactions between matter and the quantized electromagnetic field. In this paper, we derive expressions for the ground state analytical gradients in quantum electrodynamics coupled cluster theory. We also present a Cholesky-based implementation for the coupled cluster singles and doubles model. We report timings to show the performance of the implementation and present optimized geometries to highlight cavity-induced molecular orientation effects in strong coupling conditions.