  The zero-presssure zero-temperature equilibrium volume and bulk modulus are
calculated for fcc Th and Pu by two independent all-electron, full-potential,
electronic-structure methods: the full-potential linear augmented-plane-wave
(FLAPW) method and the linear combinations of Gaussian type orbitals-fitting
function (LCGTO-FF) method. The results produced by these two distinctly
different electronic-structure techniques are in excellent agreement with each
other, but differ significantly from a previous calculation using the
full-potential linear muffin-tin-orbital (FP-LMTO) method. The theoretically
calculated equilibrium volumes are nearly 10% larger than the previous FP-LMTO
calculations. While the new theoretical volume for Th is in good agreement with
experiment when the generalized gradient approximation is used, the calculated
equilibrium volume for fcc Pu remains substantially smaller than experiment in
qualitative agreement with previous calculations.
