First-principles Calculation for the Structural and Thermodynamic Properties of ReB_2

Using plane-wave pseudopotential density functional theory method,this paper studies the structural and thermodynamic properties of rhenium diboride ReB2,including the lattice parameter,the bulk modulus,and the first derivative of bulk modulus to pressure.The obtained lattice parameters are in good agreement with the available experimental data and those calculated by others.Through the quasi-harmonic Debye model,the dependences of the relative lattice parameters a/a0 and c/c0 on pressure p,the relative volume V/V0 on pressure p,the variation of the thermal expansion coefficient α with pressure p and temperature T,the dependence of the Debye temperature Θ and the heat capacity CV on pressure p and temperature T are all successfully obtained.