There is increasing evidence that vibrational entropy may significantly contribute to the entropy difference between the ordered and the disordered states of a compound. Through first-principles calculations, we investigate the magnitude of this vibrational entropy difference in ${\mathrm{Ni}}_3\mathrm{Al}$, a compound where this effect is believed to be especially large. We find the vibrational entropy difference to be essentially zero and temperature independent.

• Received 21 August 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.4911