Rotational Analysis of A2Πu−X2Σg+ System of 14N2+

The absorption spectrum of N2+ has been studied using optical-heterodyne velocity modulation spectroscopy in the near-infrared region. The observed spectral lines were assigned to the (3,1), (4,2), (5,3), (8,5) bands of the A2Πu−X2Σg+ system and the line lists were provided. The (5,3) band was studied for the first time. Fourteen rotational-resolved bands in literatures were fitted together with our observed bands and the molecular constants were obtained for υA=0−9 and υX=0−5.