2020/01/29 by Xiao Wang, Timothy C. Berkelbach, Wang, Xiao +1 · 5 citations
Engineering · Materials Science · #2D Materials and Applications #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Ga2O3 and related materials #Materials Science (cond-mat.mtrl-sci) #Perovskite Materials and Applications
paper · pdf · doi:10.48550/arxiv.2001.11050
openalex publication_date 2020/01/29 · openalex created_date 2020/02/07 · openalex updated_date 2026/07/28
We present an ab initio study of electronically excited states of three-dimensional solids using Gaussian-based periodic equation-of-motion coupled-cluster theory with single and double excitations (EOM-CCSD). The explicit use of translational symmetry, as implemented via Brillouin zone sampling and momentum conservation, is responsible for a large reduction in cost. Our largest system studied, which samples the Brillouin zone using 64 k-points (a 4x4x4 mesh) corresponds to a canonical EOM-CCSD calculation of 768 electrons in 640 orbitals. We study eight simple semiconductors and insulators, with direct singlet excitation energies in the range of 3 to 15 eV. Our predicted excitation energies exhibit a mean absolute error of 0.27 eV when compared to experiment. We furthermore calculate the energy of excitons with nonzero momentum and compare the exciton dispersion of LiF with experimental data from inelastic X-ray scattering. By calculating excitation energies under strain, we extract hydrostatic deformation potentials in order to quantify the strength of interactions between excitons and acoustic phonons. Our results indicate that coupled-cluster theory is a promising method for the accurate study of a variety of exciton phenomena in solids.