CONFIGURATION-INTERACTION CALCULATIONS ON THE P-2 MOLECULE .2. SPECTROSCOPIC PROPERTIES OF THE B (3)PI(2,G) STATE, THE B (3)PI(2,G)-A (3)SIGMA(+)(U) TRANSITION BANDS AND THE A (3)SIGMA(+)(U) STATE REVISITED

Extended basis set, multireference configuration interaction calculations have been undertaken on the b (3) Pi(2.g) and a (3) Sigma(u)(+) excited states of P-2. Reference spaces for both states were chosen according to the procedure employed previously for the X(1) Sigma(g)(+) ground state but a larger region of the potential functions with respect to our preceding work has been embraced in order to compare our results for higher experimental vibrational bands too. Compared with our previous results, the spectroscopic constants for the a (3) Sigma(u)(1) state were generally found to be in better agreement with the observed values. The theoretical values of the vibrational transitions and related Franck-Condon factors for the experimentally unknown a (3) Sigma(u)(+)-X (1) Sigma(g)(+) transition bands and the corresponding data derived by the Jarmain method simulating the experimental spectrum are found to be in much closer agreement than in our preceding report. For the b (3) Pi(2.g) state, the level of agreement with experiment was similar to what was observed in the ground state. The overall quality of the spectroscopic constants was comparable for both excited states despite the fact that the b (3) Pi(2.g) state lies at a substantially higher energy. The theoretical values of the pure vibrational transition energies, the related Franck-Condon parameters for the b (3) Pi(2.g) --> a (3) Sigma(u)(+) transition bands and the rotational transitions within the b (3) Pi(2.g) state were all found to be in good agreement with the 'measured' quantities. Vibrational and rovibrational lifetimes of the b (3) Pi(2.g) state have been calculated assuming an electric transition moment decay For the b (3) Pi(2.g) --> a (3) Sigma(u)(+) transition bands and the contributions of the pure rotational transitions to the overall lifetimes for a broad range of rotational quantum numbers (j'=2-40) are generally small. Finally, a selected set of first order properties for the X(1) Sigma(g)(+) ground state and each excited state are reported which, to the best of our knowledge, have not been measured.