High-resolution study of the (A)over-tilde2A′ → (X)over-tilde2A transition of DO2:: Analysis of the 000-000 band

The near-infrared emission spectrum of the (A) over tilde (2)A'--> (X) over tilde (2)A transition of DO2 has been studied by Fourier-transform spectrometry. The 000 --> 000 band has been recorded at high spectral resolution. DeltaK(d) = +/-1 subbands up to K-a = 12 --> K-a = 11 and K-a' = 9 --> K-a = 10, comprising lines from rotational levels up to N' = 34, have been observed. With about a factor of 5-10 lower intensity, DeltaK(a) = 0 subbands 0-0 to 6-6 were found, which are due to magnetic dipole transitions, Several local perturbations extending over 3-10 N' values were observed. Two prominent perturbation,, in the F-1 levels of the (A) over tilde (2) A'. 000, K-a, = 11 and 12 states are attributed to DeltaK(a) = 0, DeltaJ = 0, DeltaN = +/-1 interactions with the 211 level of the (X) over tilde (2) A ground state. The rotational constants for HO2 and DO2 have been used to deduce the molecular geometry of HO2 at the zero point levels of the (X) over tilde (2)A and (A) over tilde A' states. (C) 2002 Elsevier Science (USA).