  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.
