Electronic structure, Fermi surface topology and spectroscopic optical properties of LaBaCo2O5.5 compound

Abstract We have investigated the electronic band structure, Fermi surface topology, chemical bonding and optical properties of LaBaCo2O5.5 compound. The first-principle calculations based on density functional theory (DFT) by means of the full-potential linearized augmented plane-wave method were employed. The atomic positions of LaBaCo2O5.5 compound were optimized by minimizing the forces acting on atoms. We employed the local density approximation (LDA), generalized gradient approximation (GGA) and Engel–Vosko GGA (EVGGA) to treat the exchange correlation potential by solving Kohn–Sham equations. Electronic structure and bonding properties are studied throughout the calculation of densities of states, Fermi surfaces and charge densities. Furthermore, the optical properties are investigated via the calculation of the dielectric tensor component in order to characterize the linear optical properties. Optical spectra are analyzed by means of the electronic structure, which provides theoretical understanding of the conduction mechanism of the investigated compound.