LAUSR

ABSTRACT We have investigated the structural, dynamical, elastic, and electronic properties of WGe2 and W5Ge3 compounds in different phases. We have considered the C11b (tetragonal, space group I4/mmm) and C23 (orthorhombic, space group Pnma) strukturbericht phases for WGe2 compound and D81 (tetragonal, space group I4/mcm), D8m (tetragonal space group I4/mcm) strukturbericht phases for W5Ge3 compound. The structural parameters, formation enthalpies, phonon dispersion curves, elastic constants, mechanical modulus, anisotropic factors, thermal conductivities, and electronic structures have been investigated using generalised gradient approximation within in the plane wave pseudopotential density functional theory. The calculated lattice constants are in a good agreement with the experimental data. The considered phases for WGe2 and W5Ge3 compounds have a metallic character. The results indicated that all phases for compounds are both mechanically stable and dynamically stable except for W5Ge3-D81. The anisotropy in some mechanical modulus has been investigated using several elastic anisotropy indexes and directional dependence of compressibility, Young’s moduli, shear moduli, and Poisson’s ratio.