First-principles calculations and thermodynamic modeling of the Ni–Mo system

The phase equilibria and thermodynamic properties of the Ni–Mo system were analyzed by combining a first-principles approach and calculation of phase diagram (CALPHAD) technique. The first-principles calculation results indicate that Ni2Mo and Ni8Mo are stable in addition to Ni3Mo and Ni4Mo, and -NiMo is not stable at 0 K, both in contradiction to the existing phase relationships in the Ni–Mo system. The enthalpies of the mixing of the bcc and fcc solid solution phases were also predicted by first-principles calculations using the special quasirandom structures. In the present work, the non-stoichiometric -NiMo and Ni3Mo phases were modeled using threeand two-sublattice models, respectively. The Ni Mo, Ni Mo and Ni Mo phases were treated as stoichiometric compounds. Based on the first-principles data f N ©