HYPERFINE ANALYSIS OF THE MIXED A(3)PI(1) V=28 AND X(1)SIGMA(-CL-35()V=69 STATES OF (ICL))

The A (3) Pi(1), v=28 state of (ICl)-Cl-35 is known from previous stud ies to be strongly mixed with v=69 of the X (1) Sigma(+) state. Spectr a of both these mixed states are taken at high resolution to allow acc urate measurement of the hyperfine splittings due to the iodine nucleu s. The hyperfine structure in both parity components of the A state is found to be perturbed, though the common rotational-electronic induce d mixing should only affect the e components. Detailed analysis shows that hyperfine terms in the Hamiltonian also contribute significantly to the rovibronic state mixing. A Hamiltonian for these states is desc ribed that accounts for the hyperfine structure in both the A and X st ates to within the observed linewidth. The hyperfine parameters of thi s Hamiltonian, including the perturbation parameters, can be accounted for semi-quantitatively in terms of a separated atom model. (C) 1995 American Institute of Physics.