Comment on “A study of HeI photoelectron spectroscopy on the electronic structure of the nitrate free radical $NO3$” [J. Chem. Phys. 106, 3003 (1997)]

The recent photoelectron spectroscopy (PES) paper by Wang, et al. confirms our earlier photoionization mass spectrometric (PIMS) determination of the adiabatic ionization energy of $NO3.$ The PES results are also consistent with our conclusion that the ground-state neutral geometry for $NO3$ is $D3h.$ However, the PE spectrum shows a second band (and higher bands) with a vertical I.E. (ionization energy) at 13.18 eV that was absent in our photoionization efficiency spectrum. A possible reason for the apparent discrepancy is suggested and further differences between the two studies are discussed.