Semiempirical calculations on heterofullerene C59Si: structural and electronic localization

Si-doped heterofullerence C59Si is investigated via semiempirical PM3 calcu lations. Static geometric optimization shows that structural deformation oc curs in the vicinity of dopant atom and gives rise to Si-C bonds significan tly larger than the ordinary C-C bonds of the fullerene cage. Similar to th e Kohn-Sham orbitals, the Hartree-Fock HOMO and LUMO are strongly localized on the dopant Si site. We find that the overestimation of the charges on S i and its nearest neighbor C atoms in previous semiempirical calculations i s due to improper use of the MNDO method in calculating the Mulliken charge , and this problem can be solved by employing more accurate PM3 method. (C) 2001 Elsevier Science Ltd. All rights reserved.