It was shown that the thermodynamic properties of Pu metal as well as those of Pu1-xMx compounds (M = Al, Ga, In) were poorly described by traditional density functional theory but were quite well-modelled upon including magnetic interactions. The cluster variation method was used to emphasize that the presence of Ga atoms in δ-Pu phase led to a significant chemical short-range order which stabilized this phase as a function of temperature and composition. The results also indicated that Ga atoms introduced local strain fields, into the δ phase, which relaxed with increasing distance from the Ga atoms. Finally, it was shown that local relaxations were also essential to predicting correct vacancy formation and migration energies in this phase.
Thermodynamic, Alloying and Defect Properties of Plutonium - Density-Functional Calculations. G.Robert, A.Pasturel, B.Siberchicot: Journal of Alloys and Compounds, 2007, 444-445, 191-6