The conduction and valence bands near the fundamental band gap are depicted in detail in Figs. and, which provide zoomed-in views of the band structures from Figs. and. For both oxides and their polymorphs, the conduction band is well-defined, primarily derived from Ga 4s or In 5s states, and with the CBM located at the Γ point with significant dispersion around it. In contrast, the uppermost valence bands, which are predominantly For bixbyite-In 2 O 3 , however, the literature presents some conflicting results. For Ga 2 O 3 , the cubic defective spinel γ phase exhibits the smallest band gap (4.61 eV), while the rhombohedral α phase shows the largest (5.09 eV). In In 2 O 3 , the trend is more pronounced, with the bixbyite structure having the largest band gap, followed by the rhombohedral phase, and the orthorhombic polymorphs ω3, ω1, and ω2, which exhibit progressively smaller gaps. These trends generally agree with previously reported results. The results presented in Figs. and