The B 2Σ+ &rarr X 2Σ+, 2-v″ progression in the spectrum of 13C16O+

Emission spectra of the 2-v″ progression (1 &le v″ &le 6) in the B 2Σ+ &rarr X 2Σ+ system of 13C16O+ have been photographically recorded at a resolution that was high enough to achieve a clear separation of the spin components for most of the observed rovibronic transitions. Least-squares methods were used to reduce the measured line wavenumbers to the molecular constants appearing in the effective Hamiltonian taken from the work of Amiot et al (Amiot C, Maillard J P and Chauville J 1981 J. Mol. Spectrosc. 87 196-218). Merging of the data for the v′ = 2 progression with previous measurements in the v′ = 0 and 1 progressions resulted in considerably improved equilibrium molecular constants, RKR potential curves, Franck-Condon factors and r centroids for the B &rarr X system of 13C16O+.