The excited electronic states of the NO+ ion

The photoelectron spectrum of NO (Turner and May 1966) is given a new interpretation in terms of electronic states of NO+ belonging to configurations … (5σ)2(1π)32π and … 5σ(1π)42π. The close analogy with corresponding states of N2 and CO is pointed out. The long-known β Rydberg series of absorption bands of NO is shown to converge towards … 5σ(1π)42π, 3Π, but no evidence can be found for the existence of an electronic state of NO+ at the limit of the α series. The previously assumed Rydberg character of this series appears to be erroneous.