TABLE OF CONTENTS The preferred method to obtain needed free energy values is that involving the least computational burden and that provides the desired accuracy. In the order of increasing computational burden are: the method of Calphad which uses experimental data to extrapolate into the phase space of interest; the class of non-ab initio methods which are empirically or semi-empirically based schemes of predicting the desired thermodynamic potentials; the class of ab initio and first-principle procedures. In the second scheme each class of materials has its own group of predictive schemes. Also, the first-principle procedures used for different classes of materials often differ. Hence, we consider the procedures according to the class of materials. Also, since the Calphad procedure is so well established and codified we refer readers to the book by N. Saunders and A.P. Miodownik, Calphad, (Calculation of Phase Diagrams): A Comprehensive Guide Pergamon Press, Oxford, UK, 1998, for instructions as to its use.
The first (post Pauling) widely used method of predicting heats of formation is that of Miedema. (A.R. Miedema, R. Boom and F.R. de Boer, J. Less Common Met. 41, 283(1975), 45, 237(1976), 46, 67, 271(1976); F.R. de Boer, R. Boom, W.C.M. Mattens, A.R. Miedema and A.K. Niessen, Cohesion in Metals: Transition Metal Alloys, eds. F.R. de Boer and D.G. Pettifor, North-Holland, Amsterdam, 1988.) The accuracy of the predicted values varies from good to poor depending upon the...
