Structural, elastic and electronic structure of LiCu2Si, LiCu2Ge and LiAg2Sn intermetallic compounds

Structural, elastic and electronic properties of the intermetallic compounds, LiCu2Si, LiCu2Ge and LiAg2Sn, are investigated using ab initio technique as implemented in the (FP-(L) APW + lo) scheme based on the Wu–Cohen generalized gradient approximation. The computed equilibrium lattice parameters for the compounds are in good agreement with previous theoretical result and experimental data. The elastic constants reveal that the compounds are elastically stable, ductile and also exhibit large elastic anisotropy. The elastic wave velocities in the [1 0 0], [1 1 0] and [1 1 1] directions and their pressure dependence are presented and discussed. A set of isotropic elastic parameters and their related properties, namely bulk and shear moduli, Young’s modulus, hardness parameter, Poisson’s ratio, compressibility, Lame’s constant, average sound velocity, Debye temperature are predicted in the frame work of the Voigt–Reuss–Hill approximation for the polycrystalline aggregates of the compounds. Energy band structure calculations as well as the site and angular momentum projected density of states show that the compounds are metallic with mainly hybridized Cu or Ag d and Si, Ge or Sn p bands crossing the Fermi level.