Analysis of the x-ray diffuse scattering in C60 from microscopic models.

Abstract

The molecular orientational correlations in the high-temperature phase of solid ${\mathrm{C}}_{60}$ have been analyzed through calculations of the diffuse scattering for different microscopic models of intermolecular interactions. A mean-field theory up to the $l=12$ terms in the multipolar expansion accounts for the main features of the complex x-ray diffuse scattering in the ${Q}_{1}\ensuremath{\simeq}3.3$ ${\mathrm{\AA{}}}^{\ensuremath{-}1}$ halo. Instabilities relative to competing phases are revealed. It is also shown that diffuse scattering calculations are good probes for testing the intermolecular interaction models.