The ground and the excited state properties of the fullerene-linked quarter-thiophenes dyad were studied theoretically with the quantum chemistry method. To reveal the excited state properties of them in the vertical absorption process, the energies and densities of the HOMO and LUMO, the intramolecular charge transfer (ICT), locally excited (LE) are studied with transition density matrix, charge difference density and the off-resonant and resonant non-linear polarizabilities. The conclusion is drawn that there are also some intramolecular charge transfer (ICT) excited states, which result from large data of off-resonant and the resonant nonlinear polarizabilities in the vertical absorption process. (c) 2005 Elsevier B.V. All rights reserved.