First-principles elastic constants and phonons of $\delta$-Pu

Elastic constants and zone boundary phonons of $\delta$-Pu have been calculated within the density-functional theory. The electronic structure is modeled by disordered magnetism utilizing either the disordered local moment or the special quasi-random structure techniques. The anomalously soft C$^ {prime}$ as well as a large anisotropy ratio of $\delta$-Pu is reproduced by this first-principles model. Also the measured phonons for $\delta$-Pu compare relatively well with their theoretical counterpart at the zone boundary.