CALCULATED ENTHALPIES OF MIXING OF MNO MGO AND NIO/MGO/

Calculations are reported of the enthalpies of mixing of MnO/MgO and N iO/MgO based on temperature-dependent lattice statics and dynamics and ab initio periodic Hartree-Fock methodology with a posteriori correct ions for electron correlation derived from density-functional theory. For MnO/MgO both methodologies predict enthalpies of mixing that are c lose to those reported by Hahn and Muan (J. Phys. Chem. Solids, 1961, 19, 338). For NiO/MgO, on the other hand, classical simulations predic t positive deviations from ideality in contrast to Hartree-Fock calcul ations which predict small negative deviations in agreement with the e xperimental data of Davies and Navrotsky (J. Solid State Chem., 1981, 38, 264).