The nature of the molecular motion of C-60 in crystalline C-60. 2CHBr(3) has been determined by solid-state NMR. In the 193-295 K temperature range the C-60 molecules undergo fast isotropic reorientation, similar to that in pure C-60. The activation energy of reorientation of the C-60 cages is 65 meV, with a corresponding rotational diffusion constant at 298 K of 9.6 x 10(-11) s(-1).