THEORETICAL-STUDY OF BOUND-STATES OF AR-NO

We have used a recent ab initio CEPA (coupled electron pair approach) potential energy surface as well as two earlier potential energy surfaces to calculate the energies of the lowest rovibronic levels of the nearly degenerate electronic ground states ((2)A' and (2)A'') of the Ar-NO(X(2) Pi) complex. We use a variational approach which includes the rotation-vibration, electron angular, and spin momenta coupling but neglects nuclear spin coupling. The results allow a direct comparison with measurements of high-resolution rotational spectra in the vibrational ground state. Predictions are also made for the positions of bound rovibronic levels (J = 1/2), which have not yet been observed.