Local density-functional total-energy calculations reveal a model for
quasispherical nested fullerenes that corresponds to a local minimum o
n the carbon energy surface and involves a change in ring statistics.
The model scales well with fullerene size, is consistent with a recent
sputtering mechanism for their formation, and simulated high-resoluti
on TEM images coincide with experimental observations. The calculation
s yield interlayer energies in the 11-15 meV/atom range for two C-840
molecules and indicate that these quasispherical C-840 molecules shoul
d be semiconducting with a very small gap.