An \textit{Ab Initio }Study of FCC Pu$_{1-x}$Ga$_{x}$

As is known, the addition of a few atomic percent of Ga stabilizes the fcc $\delta $ -- phase of Pu at room temperature. In this work, conventional and hybrid density functional theory have been used to study the electronic, geometric, and magnetic structure properties of Pu$_{1-X}$Ga$_{x }$with varying Ga concentrations in the fcc $\delta $ phase. The calculations have been performed using the all-electron full-potential linearized augmented plane wave plus local orbitals basis method and the \textit{WIEN2k }software. Each compound has been studied at the non-magnetic, ferromagnetic, and anti-ferromagnetic configurations with and without spin-orbit coupling (SOC) and full geometry optimizations. The ground state structures are found to be anti-ferromagnetic with a contraction of the lattice constants from pure $\delta $-Pu. The obtained lattice parameters are in satisfactory agreement with experimental data.