“…The bands are assigned to the Whereas the ground states and the b 1 S / states are well D£ Å 0 transitions of the a2 r X 2 1 systems. Vibrational analyknown for all 20 group V halides (1,2), the a 1 D states ses have yielded first spectroscopic constants of the a2 and have been observed only for seven of the molecules (NF improved data for the X 1 0 / and X 2 1 states. (1), NCl (3), NBr (3), PF (1), AsF (1), SbF (1), and BiF (4)).…”