# Gaussian-based coupled-cluster theory for the ground state and band structure of solids

## TL;DR

This paper applies Gaussian-based coupled-cluster methods to accurately compute ground-state properties and band structures of covalent semiconductors like diamond and silicon, demonstrating high-precision results for solids.

## Contribution

It introduces a Gaussian-based coupled-cluster approach for solids, enabling detailed ground and excited state calculations with high accuracy.

## Key findings

- Accurate lattice constants, bulk modulus, and cohesive energies obtained.
- Quasiparticle band structures and gaps computed with extensive Brillouin zone sampling.
- Method demonstrates feasibility for large-scale solid-state quantum chemistry calculations.

## Abstract

We present the results of Gaussian-based ground-state and excited-state equation-of-motion coupled-cluster theory with single and double excitations for three-dimensional solids. We focus on diamond and silicon, which are paradigmatic covalent semiconductors. In addition to ground-state properties (the lattice constant, bulk modulus, and cohesive energy), we compute the quasiparticle band structure and band gap. We sample the Brillouin zone with up to 64 k-points using norm-conserving pseudopotentials and polarized double- and triple-zeta basis sets, leading to canonical coupled-cluster calculations with as many as 256 electrons in 2,176 orbitals.