First-principles calculations of elastic properties of LiBC

We employ all-electron full-potential linearized muffin-tin orbital method (FP-LMTO) within the frame of density functional theory (DFT) to calculate the equilibrium lattice parameters, five independent elastic constants and Debye temperature of LiBC. The equilibrium lattice parameters obtained are in good agreement with experimental data and those by others. The Debye temperature ΘD from the calculated elastic constants of LiBC is higher than that of MgB2 and TiB2. The anisotropies of the three types of elastic waves in LiBC at zero pressure have been discussed. It is found that the anisotropy of compressional waves in LiBC is considerably larger than that in MgB2 and TiB2.