Multipole approach to orientational interactions in solid C60.

Abstract

We calculate electrostatic multipole moments of C 60 up to l=18 using the quantum-mechanical charge distribution with icosahedral symmetry obtained from ab initio calculations. It is found that the second nonzero moment (l=10) is comparable to the first nonzero moment (l=6). The values of several low-order multipole moments are almost ten times smaller than those found from the charge distribution of recently proposed potential models and thus the actual Coulomb interaction between C 60 is much smaller than previously predicted. Much better agreement with calculated multipoles is obtained from a model which introduces point charges at the center of hexagonal and pentagonal plaquettes, following the physical arguments of David et al