Tight-binding molecular dynamics study of C-60, C-116 and C-120

The geometric structures of C-60, C-116 and C-120 in their ground states are obtained by tight-binding dynamic molecular simulation (TBMD). We find that the ground state of C-60 has high symmetry, I-h, but C-116 and C-120 have low symmetry, D-2h. The energy bands and vibrational modes of C-116 and C-120 are complex compared with C-60. Some of them can be easily recognized as C-60 derived and are no longer degenerate but very close, and others are produced by the interaction and relative movement between two C-58 or two C-60.