Crystal structure and disorder in solid C70.

Detailed analysis of the room-temperature X-ray powder-diffraction data of pure, as-prepared, solid C 70 is reported. C 70 adopts a hcp structure (space group P6 3 /mmc) with a=10.53(1) A and c=17.24(1) A. Quantitative agreement between the observed and calculated diffraction patterns require (a) orientational disorder among the molecules, (b) the presence of ~5% of stacking faults, and (c) a fraction of the sample to be either microcrystalline or amorphous.