  The electronic structures of fcc Ce are calculated for large supercells with
varying disorder by use of density-functional theory. Thermal disorder induces
fluctuations of the amplitude of the magnetic moments and an increase the
average moments in the high-volume phase. The ferro-magnetic solutions move
towards lower volume than in calculations for the perfectly ordered lattice.
Therefore, disorder contributes via entropy to the stabilization of the
$\gamma$ phase at high $T$, and it is important for an understanding of the
$\alpha-\gamma$ transition. Core level spectroscopy would be a mean to detect
disorder through the spread of Madelung shifts and local exchange splittings.
