NANO LETTERS
Reply to Comment on “Electronic Transport, Structure, and Energetics of Endohedral Gd@C82 Metallofullerenes”
2005 Vol. 5, No. 11 2341
L. Senapati, J. Schrier,* and K. B. Whaley Department of Chemistry and Pitzer Center for Theoretical Chemistry, UniVersity of California, Berkeley, California 94720-1460 Received September 21, 2005
The C2V symmetry axis of C82 is incorrectly described in ref 1. The true C2V axis passes through the center of one hexagonal ring and bisects a C-C bond on the opposite side of the fullerene that is surrounded by four hexagons. On page 2074 and in Figure 2 of ref 1 we incorrectly described the position of the endohedral Gd atom as situated inside the ring and adjacent to the C-C double bond on the C2V axis. Figure 2 shows instead the Gd atom is located inside the ring and adjacent to a C-C double bond that is surrounded by three hexagons and one pentagon and is thus not on the C2V symmetry axis. We have performed additional calculations to verify that that minimum energy structure shown in Figure 2 is indeed correct. In these calculations the Gd atom was placed at several distances from the C-C bond on the true C2V axis and then allowed to relax to the nearest minimum energy position. In all cases, the Gd atom moved away from the C2V axis C-C bond, toward the C-C bond in a nearby hexagonal ring. The lowest total energy of these near-C2V C-C bond structures was 252 meV (249 meV) higher than the M ) 7 (M ) 9) ground-state geometry reported in ref 1. Figure 2 thus shows the correct minimum energy structure. Only the statements that the nearest C-C bond is on the C2V symmetry axis, made in the caption of Figure 2 and on pages 2074 and 2077, are incorrect.
10.1021/nl0518831 CCC: $30.25 Published on Web 10/08/2005
© 2005 American Chemical Society
We note that the density functional theory (DFT) minimum energy structure is therefore not in agreement with the maximum entropy method (MEM)/Rietveld-based X-ray synchrotron powder diffraction structure for 82 reported by Nishibori et al.,2 contrary to what was stated on page 2074. However, it has been found that the MEM/Rietveld method does not reliably determine the structure of Sc3@C823,4 and Sc2@C665 metallofullerenes. The DFT minimum energy structure of the former has very recently been confirmed by 13 C NMR experiments.3 Similar experiments for 82 would better distinguish the true ground-state structure in this case. The authors thank Lei Wang and Deren Yang (Zhejiang University, China) and Liu Lei (Institute of High Energy Physics, China) for clarifying the symmetry discrepancy. References (1) Senapati, L.; Schrier, J.; Whaley K. B. Nano Lett. 2004, 4, 2073. (2) Nishibori, E.; Iwata, K.; Sakata, M.; Takata, M.; Tanaka, H.; Kato, H.; Shinohara, H. Phys. ReV. B 2004, 69, 113412. (3) Iiduka, Y.; Wakahara, T.; Nakahodo, T.; Tsuchiya, T.; Sakuraba, A.; Maeda, Y.; Akasaka, T.; Yoza, K.; Horn, E.; Kato, T.; et al. J. Am. Chem. Soc. 2005, 127, 12500. (4) Kobayashi, K.; Nagase, S. Chem. Phys. Lett. 1999, 313, 45. (5) Kobayashi, K.; Nagase, S. Chem. Phys. Lett. 2002, 362, 373.
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