Abstract
The results of ab-initio calculations of the electronic structure and magnetism of the new superconductor RbEuFe
As
are reported. The electronic band structure and the density of states are presented and discussed in detail. The electric charge density distributions along different crystallographic planes are presented, and the origin of the chemical bonding between the constituent atoms is discussed in detail. The evidence is provided for the existence of a mixture of ionic, covalent, and metallic bonding. It is demonstrated that the magnetic moment is mainly due to the strongly localised Eu
states. An almost negligible magnetic moment carried by the Fe atoms is shown to be due to the symmetry of the Fe spin-up and spin-down states. It is demonstrated that the electrical and chemical properties of RbEuFe
As
are closely linked with the presence of the Fe
states in the Fermi energy region. The Fermi surfaces show the presence of hole-like and electron-like pockets, respectively, at the center and corners of the Brillouin zone. The results of the calculations of the elastic properties and the
Fe and
Eu hyperfine-interaction parameters are also presented.