Study of the polarizability of fullerenes with a monopole-dipole interaction model

Static dielectric properties of some fullerenes and fullerene-based molecules are studied using a Gaussian renormalized monopole-dipole interaction model. Many kinds of molecules have been constructed on the computer: fullerenes with icosahedral shape, Stone-Wales rounded fullerenes, and carbon onions constructed with these two types of fullerenes. The geometry optimization has been performed with the second-generation reactive empirical bond order potential energy [D.W. Brenner, J. Phys. Condens. Matter 14 (2002) 783]. As expected, the molecular polarizability of spherical and icosahedral fullerenes is found to vary linearly with the cube of their mean radius. The contribution of internal layers in multi-shell onions is very small due to a strong screening. The presence of defects in spherical fullerenes decreases the atomic density and the screening effects between atoms, which yields a slight increase of the dielectric response. Some examples of peanut-shape fullerenes, which have been observed experimentally, are also considered. (c) 2007 Elsevier B.V. All rights reserved.