  We calculate the band gaps of 12 inorganic semiconductors and insulators
composed of atoms from the first three rows of the periodic table using
periodic equation-of-motion coupled-cluster theory with single and double
excitations (EOM-CCSD). Our calculations are performed with atom-centered
triple-zeta basis sets and up to 64 $k$-points in the Brillouin zone. We
analyze the convergence behavior with respect to number of orbitals and number
of $k$-points sampled, using composite corrections and extrapolations to
produce our final values. When accounting for electron-phonon corrections to
experimental band gaps, we find that EOM-CCSD has a mean signed error of
$-0.12$ eV and a mean absolute error of $0.42$ eV; the largest outliers are C
(error of $-0.93$ eV), BP ($-1.00$ eV), and LiH ($+0.78$ eV). Surprisingly, we
find that the more affordable partitioned EOM-MP2 theory performs as well as
EOM-CCSD.
