These assignments are informed by the results of our FC simulations as well as the previously reported photoelectron spectrum of Ramond et al. As features A1-13 are largely reproduced in the simulated spectra, they are assigned to Franck-Condon (FC) allowed transitions within the 2 , corresponding to A2 and A3, respectively), the appearance of the FC-allowed 2 0 3 transition (A9), and several combination bands including A5, A6, and A8 (see Table ).