Density-functional study of bcc Pu–U, Pu–Np, Pu–Am, and Pu–Cm alloys

Density-functional theory previously used to describe phase equilibria in the γ-Pu–U–Zr alloys [A. Landa, P. Söderlind, P.E.A. Turchi, L. Vitos, A. Ruban, J. Nucl. Mater. 385 (2009) 68; A. Landa, P. Söderlind, P.E.A. Turchi, L. Vitos, A. Ruban, J. Nucl. Mater. 393 (2009) 141], is extended to study ground-state properties of the γ-Pu–Np, γ-Pu–Am, and γ-Pu–Cm solid solutions. Calculated heats of formation are compared with CALPHAD assessments where possible. We discuss how the heat of formation correlates with the charge transfer between the alloy components.