A CASSCF study of the cyclopentadienyl radical: conical intersections and the Jahn-Teller effect

摘要

The D_5h Jahn-Teller crossing and associated C_2v minima and saddle points in cyclopentadienyl have been optimised at the CASSCF/cc-pVDZ level of theory. The C-2v structures were characterised by computing analytic force constants. Zero point energies calculated for all C_5H_4D and C_5HD_4 isomers of the C_2v minima suggest an alternative interpretation of the experimentally observed degeneracy resolution (L. Yu, D.W. Cullin, J.M. Williamson, T.A. Miller, J. Chem. Phys. 98 (1993) 2682).