The fundamental band gap of 1.95 eV calculated using hybrid DFT occurs at Γ and is in line with the experimental band gaps of 1.9-2.0 eV. The band gaps of 2.19 eV and 2.16 eV obtained by McColl and Corà, using HSE06 without Van der Waals dispersion corrections, are slightly greater. It is worth nothing, however, that these calculations did not use a plane-wave basis set and computed the band structure based on the k-point path for a simple rather than body-centered tetragonal system.