Study of the structural and electronic properties of FeO at the LDA and GGA level

Due to its strongly correlated insulating nature, FeO is used in various catalytic applications. Structural and electronic properties of FeO are investigated by using density functional theory (DFT) with the BAND code in Amsterdam Density Functional (ADF) software at ambient conditions. The generalized gradient approximation (GGA) and local density approximation (LDA) without and with the Hubbard potential (U eV) are used to investigate the structural and electronic properties of FeO. Geometric optimization of FeO is carried out by using the LDA and GGA method. CAPZ (Ceperley-Alder-Perdew-Zunger) and PBE (Perdew-Burke-Ernzerhof) are used as exchange correlation potentials for the LDA and GGA, respectively. The Hubbard potential is optimized and U= 0.6 eV is used to overcome the under-estimation of the band gap of FeO in both approximations. The band structure shows the metallic nature of FeO with the GGA and LDA while band gap of 2.34 and 2.08 eV is observed by using GGA+U and LDA+U, respectively. Our calculated band gap value with the GGA+U is in good agreement with the reported experimental value, i.e. 2.4 eV. The total and partial density of states are also plotted to show the band structure. To the best of our knowledge, no study has been reported yet at the U= 0.6 eV value of the Hubbard potential.