The first-principle DFT calculations were performed using the Vienna ab initio simulation code (VASP) . The Generalized Gradient Approximation (GGA) in the parametrization by Perdew, Burk, and Ernzerhof combined with the projector augmented wave (PAW) method was used . A cut-off energy of 520 eV was used, while the Monkhorst-Pack Γ-centered 5×5×8 k-point mesh was used for tetragonal RhO2, and 4×4×3 k-point mesh was set for orthorhombic Rh2O3. For Density of States calculations, partial occupancies were treated using the tetrahedron method with Blöchl correction .