The assignments were made on the basis of relatively low-level calculations carried out using the Gaussian 94 program suite. (Restricted Hartree-Fock calculations with 3-21G* basis.) The experimental Raman spectra were then matched to the overall patterns of the ab initio calculations. In general the frequencies were calculated frequencies were over-estimated. The small unassigned peaks in the spectrum in the region 1600 cm-1 and 2800 cm-1 are most probably combination bands.
The animations of adamantane and diamantane have been produced using the optimized geometry and maximum displacements from the ab initio calculations. The individual frames have been calculated using a simple sinusoidal interpolation. The animation of the diamond lattice uses the fact that all the individual unit cells are in phase with one another (i.e. k=0). The diamond lattice can be thought of as two face centered cubic lattices and in this case the two lattices as a whole are moving relative to one another. Again the animation uses a simple sinusoidal interpolation for each frame.