Structural and electronic properties of Er_0.5Lu_0.5B₂ and LuB₂ compounds by using the PBE0 hybrid functional

We report first-principles calculations to determine the structural and electronic properties of Er_0.5Lu_0.5B₂ and LuB₂ compounds, by using Density Functional Theory (DFT) and Full Potential Linearized Augmented Plane-Waves (FP-LAPW) method. For the description of the electron-electron interaction was used the Local Density Approximation (LDA), Generalized Gradient Approximation of Perdew-Burke-Ernzerhof (GGA-PBE) and PBE0 hybrid functional. From the density of states (DOS), it is found that the addition of a fraction of the exact Hartree- Fock exchange energy in PBE approximation, evidence the localization of the 4f-Er and 4f-Lu orbitals, which favours the polarization of the electronic spins of these orbitals in LuB₂ and Er_0.5Lu_0.5B₂ compounds. The PBE0 scheme is justified because it describes of more appropriate manner the electronic and magnetic properties of strongly correlated systems than the LDA and PBE approaches.