This body of work motivated us to re-investigate the NO3¯ photoelectron spectrum using cryo-SEVI. A representative set of spectra is shown in Figure . The grey spectrum is an overview spectrum taken at h=35137 cm -1 , while the black spectra represent three higher resolution composite spectra that have been concatenated and normalized to the overview spectrum. There are several key points of comparison between the cryo-SEVI in Fig. and photoelectron spectra in Fig. . First, the peaks in the cryo-SEVI spectra, particularly in the black spectra, are on average 10 cm -1 wide, considerably narrower than the corresponding features in the PE spectrum. The position of the vibrational origin, peak A, yields a refined value of 3.9289 (14) eV for the electron affinity of NO3. Secondly, the 4 1 1 hot band in the photoelectron spectrum has disappeared in the cryo-SEVI spectrum, a consequence of better vibrational cooling in the latter spectrum. In contrast, peak a in the PE spectrum, assigned to the 4 0 1 transition, is clearly present in the cryo-SEVI spectrum as peak B and thus is not a hot band. Hence the alternative assignment proposed by Hirota is incorrect.