Spin polarized density functional theory calculations of the electronic structure and magnetism of the 112 type iron...

Using density-functional theory, we investigate the electronic, magnetic, and hyperfine-interaction properties of the 112-type iron-pnictide compound [Formula: see text], which is isostructural to the high-temperature iron-based superconductor [Formula: see text]. We show that the band structure of [Formula: see text] is similar to that of the 112-type compounds' family, with hole-like and electron-like bands at the Brillouin-zone center and corners, respectively. We demonstrate that the bands near the Fermi level originate mainly from the Fe atoms. The presence of a mixture of ionic and covalent bonding is predicted from the charge-density and atom-resolved density-of-states calculations. There is good agreement between the calculated hyperfine-interaction parameters with those obtained from the [Formula: see text]Fe and [Formula: see text]Eu Mössbauer measurements. The spatial distribution of atoms in [Formula: see text] leads to an in-plane 2D magnetism. Moreover, ab-initio calculations predict the compound's magnetic moment and the magnetic moments of each constituent atom. Also, the density of states profile provides insight into the relative magnitude of these moments. Electronic structure calculations and Fermi surface topology reveal various physical and chemical properties of [Formula: see text]. Valence electron density maps indicate the co-existence of a wide range of chemical bonds in this system, and based on structural properties, the transport characteristics are deduced and discussed. A thorough analysis of the atomic structure of [Formula: see text] and its role in the bond formation is presented.