FIRST-PRINCIPLES CALCULATION OF VIBRATIONAL ENTROPY FOR FE-AL COMPOUNDS

In this paper, we calculated the difference in vibrational entropy bet ween chemically disordered and ordered Fe-Al compounds. The procedure of calculation is as follows: (1) Calculating the total-energy curves by using the ab initio band calculation method tight-binding linear mu ffin-tin orbital; (2) inverting the interatomic potentials involved in these Fe-Al compounds based on the lattice inversion method; (3) calc ulating the phonon dispersions and density of states and consequently the vibrational entropy by using these ab initio inverted interatomic potentials. The calculated results are in good agreement with experime ntal data. [S0163-1829(98)02439-4].