Electronic structure of small fullerenes: Evidence for the high stability of C-32

The electronic structure of small fullerenes determined experimentally by a nion photoelectron spectroscopy is compared with calculations. A huge mass signal and a large gap of 1.3 eV comparable to the gap of C-70 have been fo und for C-32, indicating that this cluster is the most stable fullerene bel ow C-60 Also C-36, C-45, and C-50 exhibit large gaps and surprisingly high stabilities. The criteria for the selection of clusters sufficiently stable to form a cluster material are discussed.