On sign reversal of the linear thermal expansion coefficient of fullerite C-60 at helium temperatures

An attempt is made to interpret the low-temperature negative thermal expans ion of solid C-60 on the basis of an assumption concerning the freezing of all (thermally activated) rotations and the formation of anisotropic interm olecular potential ensuring libron vibrations of fullerene molecules in the equilibrium position displaced relative to the isotropic potential minimum . (C) 1999 American Institute of Physics. [S1063-777X(99)01610-2].