First-principles density functional theory (DFT) calculations were performed using the Vienna Ab initio Simulation Package (VASP). The generalized gradient approximation of Perdew-Burke-Ernzerhof (PBE) was used as the exchange correlation functional. The core and valence electrons were treated with the projector-augmented wave (PAW) method. A plane-wave energy cutoff of 340 eV was used, and a Hubbard on-site energy correction of U= 3 eV was applied to the Y-d orbitals. The electronic structure of Y 2 Te 3 was calculated from the charge density of the fully-relaxed structure using the tetrahedron method for k-point integration and a Γ-centered 8 × 8 × 4 k-point mesh. It is well-known that the PBE functional underestimates the band gap of semiconductors and insulators, which directly affects the defect formation energy and resulting charge carrier concentrations. We address the band gap underestimation by shifting the band edge positions based on GW quasiparticle energy calculations. Due to the presence of Te, we also included band edge shifts due to relativistic spin-orbit coupling (SOC) effects. The two band edge shifts together result in valence (conduction) band shifts of -0.511 (+0.490) eV relative to the PBE band edges, yielding a band gap of 1.78 eV.