Ab initio study of the structural, electronic and elastic properties of AgSbTe _2, AgSbSe _2, Pr _3AlC, Ce _3AlC, Ce _3AlN, La _3AlC and La _3AlN compounds

摘要

In this paper, we study the structural, electronic and elastic properties of the ternary AgSbTe _2, AgSbSe _2, Pr _3AlC, Ce _3AlC, Ce _3AlN, La _3AlC and La _3AlN compounds using the full-potential linearized augmented plane wave (FP-LAPW) scheme and the pseudopotential plane wave (PP-PW) scheme in the frame of generalized gradient approximation (GGA). Results are given for the lattice parameters, bulk modulus, and its pressure derivative. The calculated lattice parameters are in good agreement with experimental results. We have determined the full set of first-order elastic constants, shear modulus, Youngs modulus and Poissons ratio of these compounds. Also, we have presented the results of the band structure, densities of states, it is found that this compounds metallic behavior, and a negative gap →R for Pr _3AlC. The analysis charge densities show that bonding is of covalent-ionic and ionic nature for AgSbSe _2 and AgSbTe _2 compounds.