The two lowest energy 2<i>A</i>′ states of NO2

Abstract

The 2A1 ground state of NO2 and the so-called 2B2 excited state are shown to form a strongly coupled pair of 2A′ states when asymmetric distortion is considered. This coupling is of the Jahn–Teller type although the degeneracy between the states is accidental and the normal coordinates are not equivalent.