Structural and electronic properties of XSi₂ (X = Cr, Mo, and W)

The structural and electronic properties of metal silicides XSi₂ (X = Cr, Mo, and W), which crystallize in tetragonal structure, are investigated systematically using the first-principle density functional theory. The total energies are computed as a function of volume and fitted to the Birch equation of state. The ground-state properties such as equilibrium lattice constants a₀ and c₀, bulk modulus B, its pressure derivative B, B′, and the density of states at the Fermi level, N(E_F), are calculated and compared with other experimental and theoretical results, showing good agreement. The calculated band structure indicates that XSi₂ compounds are semimetallic in nature. From the present study, we predict the structural and electronic properties of CrSi₂ in the tetragonal phase and indicate that CrSi₂ is energetically more stable than MoSi₂ and WSi₂. Analyzing the bonding properties of the three metal silicides, we observe that WSi₂ has a strong covalent bonding due to W 5d electrons