Single crystal x-ray diffuse scattering studies of the intermolecular interactions in solid C60

Current microscopic models of the C60 intermolecular interactions fail to give an accurate description of the ordering phenomena in solid C60, where orientational correlations of the fullerene molecules play a leading role. At room temperature these orientational correlations produce x-ray diffuse scattering intensity modulations whose analysis is a good test for the microscopic models. Below the 259K transition, the remaining x-ray diffuse scattering was measured up to large wave vector values. Its analysis confirms that the low-temperature structure is characterised by two nearly degenerate and randomly distributed orientations of the C60 molecules.