This value can be compared to the minimum of the conical intersection located at about 1000 cm -1 higher in energy, at 3,174 cm -1 above the origin. Our Hamiltonian is not suitable for describing the dissociation of the molecule, therefore, we expect a discrepancy with the experiment as the energy gets closer to the dissociation threshold located at 4,898±3 cm -1 above the origin. Figure shows the assigned spectrum and Table lists the decomposition of all peaks in the region of up to 3100 cm -1 . We compare the resulting assignment with the high- peak of the simulation is aligned. The origin of the simulated spectrum is red-shifted by 170 cm -1 relative to the experimental origin at 101,020.5 cm -1 . This discrepancy is within our error estimate for the vertical ionization energy (30 meV=240 cm -1 ).