Performance of periodic EOM-CCSD for band gaps of inorganic semiconductors and insulators

Abstract: 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.