M. D. ALLEN, K. M. EVENSON, Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80303-3328; AND J. M. BROWN, The Physical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom.
Vibration-rotation transitions between the (010) µ2 - - (000) X2 r vibronic states, were recorded using far-infrared laser magnetic resonance (FIR-LMR) spectroscopic techniques. These transitions occur near 200 cm-1 for the (010) µ2 - - (000) X2 1/2 transition and 160 cm-1 for the (010) µ2 - - (000) X2 3/2 transition. This is the first direct measurement of the 2 band of CCN and with the inclusion of optical data, similar to the one found in the paper by Kohguchi et al.,, microwave data from Ohshima and Endo, and spin-orbit data\footnoteCalculated from data reported in M. Kakimoto and T. Kasuya, J. Molec. Spectros. 94, 380-392 (1982) and
~~~K. Kawaguchi, T. Suzuki, S. Saito, and E. Hirota, J. Molec. Spectros. 106, 320-329 (1984). a least squares fit has resulted in an accurate determination of molecular parameters for the ground and the (010) µ2 - states. The data were fit using an N2 effective Hamiltonian modified to include the Renner-Teller effect.