Calculation of rovibronic intensities for triatomic molecules in double-Renner-degenerate electronic states: Application to the (X)over-tilde2A and (A)over-tilde2A′ electronic states of HO2

An algorithm and a computer program implementing it are presented for calculation of the rovibronic intensities for a triatomic molecule in a double-Renner-degenerate electronic state. The program has been applied to investigate, by theoretical simulation, the absorption spectrum of HO2 in the (X) over tilde (2)A '' and (A) over tilde (2)A' electronic states. The spectrum simulations are based on potential energy functions, electric dipole moment functions, and electric dipole transition moment functions constructed from ab initio values calculated at the core-valence MR-SDCI+Q/[cc-pVQZ (H), aug-cc-pCVQZ (O)] level of theory. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3139916]