15min:

KANA TAKEMATSU, NATHAN EDDINGSAAS AND MITCHIO OKUMURA, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125; JOHN STANTON, Department of Chemistry, University of Texas at Austin, Austin, TX 78712.

The JT effect in the A²E'' of NO₃ is poorly understood. A preliminary spectrum of the vibronically-allowed A X transition, coupled with ab initio calculations, shows moderate JT activity in the A state. Vibronic bands exhibit either static or dynamic JT distortions depending on the vibrational level of the upper A state. The picture of the A state is however incomplete. For example, in the E''øtimese'=a₁''øplusa₂''øpluse'' manifold, while the splitting would provide a direct measure of the JT strength, only the a₁'' levels have been observed. We have gained new insight into the A state by examining the hot bands of NO₃ which access previously unobserved dark levels of the A state.