First-principles study of electronic structure for the Laves-phase compounds HfFe2 and HfV2

Ab initio calculations have been performed to calculate the density of states (DOS), energy bands and charge density distributions of paramagnetic cubic Laves-phase HfFe2 and HfV2 based on the method of augmented plane waves plus local orbital to reveal its electronic structure. The results revealed the overlap of charge densities between the neighboring Fe–Fe (V–V) atoms. This showed a rather strong covalent bonding between Fe–Fe (V–V) atoms and a metallic bonding between Hf–Fe (Hf–V) atoms. The Fe-d states are also more spatially confined than those of V-d, therefore, the hybridization of the valence electrons between Hf–V are stronger than that between Hf–Fe, leading to a stronger covalent bonding in HfV2 compound. These results are helpful to understanding the physical and chemical properties for both compounds.