The IR spectra of neutral Ti8C12 metallocarbohedryne (Met-Car) and its cation are predicted based on the complete active space self-consistent field (CASSCF) method. The blue shift predicted for the C-C stretching frequency in Ti8 C12+ with respect to neutral Ti8C12 is in agreement with experimental results. The triply degenerate C-C stretching mode splits into doubly and singly degenerate modes as a result of the Ti8C12 Jahn-Teller distortion from Td to D2d symmetry. The splitting is small for the neutral cluster, but it is significant for the cation.
Bibliographical noteFunding Information:
This work was supported by a grant from the Air Force Office of Scientific Research. Computer time was made available at the Department of Energy NERSC center for some of the larger calculations. The calculations in this work were performed in part on an IBM workstation cluster made possible by grants from IBM in the form of a Shared University Research grant and the United States Department of Energy. The authors thank Professor Michael Duncan and Dr. Michael Schmidt for helpful discussions.