OsN2: Crystal structure and electronic properties
Abstract
Osmium nitride belongs to a family of nitrides synthesized recently at high pressures from their parent elements. Here we show, based on first-principles calculations, that the crystal structure of osmium nitride is isostructural to marcasite. Excellent agreement is obtained between the authors' results and x-ray, Raman, and compressibility measurements. In the OsN2 marcasite structure single-bonded N2 units occupy the interstitial sites of the Os close-packed lattice, giving rise to a metallic compound. A comparison between the formation energies of OsN2 and PtN2 explains the similar thermodynamic conditions of formation reported experimentally for the two compounds.
Keywords
osmium compounds
crystal structure
ab initio calculations
compressibility
Fermi level
electronic density of states
interstitials
Raman spectra
61.66.Fn
81.40.Lm
62.20.Fe
78.30.Hv
61.72.Ji
71.20.Ps
Inorganic compounds
Deformation plasticity and creep
Deformation and plasticity
Other nonmetallic inorganics
Point defects and defect clusters
Other inorganic compounds