The optical response of the lowest energy members of the C20 family is
calculated using time-dependent density functional theory within a real-space,
real-time scheme. Significant differences are found among the spectra of the
different isomers, and thus we propose optical spectroscopy as a tool for
experimental investigation of the structure of these important clusters.Comment: 11 pages, 2 figures. To be published in J. Chem. Phy