Study of the B 2Σu+, A 2Πu and X 2Σg+ Electronic States of N2+

The spectra of the (12,6), (11,5) and (7,2) bands of theA2Πu-X2Σ+gsystemand the (1,5) band of the B2Σ+u-X2Σ+gsystem of N2+have been observed and analyzed in the visible region between 16800~17573 cm-1using optical heterodyne magnetic rotation enhanced velocity modulation spectroscopy. This paper has derived the effective Hamiltonian matrixes including the perturbation terms for analysis of the rovibronic spectrum in a diatomic molecule, revealed and explained the mechanism of the perturbation between the A2Πuand B2Σ+ustates of N2+. The analysis shows that the vibronic levels A2Πu (v=11) and B2Σ+u (v=1) have a strong interaction atJ=13.5 (for elevel) and 9.5 (for flevel). As a result, the perturbation constantsξeandηeforA2Πuand B2Σ+ustates ofN2+are obtainedwith the values of -34.1350 (59) cm-1and 1.09756(30) respectively.