Résumé:
We studied the structural, elastic and thermodynamic properties of MnX (X = S and Se) by applying the first principle of thermodynamics. The exchange-correlation function used the generalized Perdew-Berke-Ernzerhof (GGA-PBE) gradient approximation under the Espresso Quantum code. The estimated structural properties of these compounds are in excellent agreement with the experimental data. The stability of the compounds was discussed on the basis of the calculated elastic constants C_ij, which are in good agreement with the experimental results. Then, the thermodynamic properties of MnX materials are calculated under the action of the Gibbs function. In addition, the influence of temperature and pressure on heat capacities, coefficients of expansion and modulus of compressibility were calculated and discussed.
