As compared to that in Fig. , the spectrum reported in Fig. is computed using the same value of η but a much larger value of r 0 . The result is that the harmonic progression no longer drops nearly as precipitously at the 30th harmonic, as it does for the smaller turn-on radius, but persists all the way to the 100th harmonic. Alongside the anticipated odd harmonics are a set of spurious, parallel features. Conversely, when r 0 is reduced to 4.0 bohr (Fig. ), keeping η the same, the result is that FIG. : HHG spectra for H2, computed at the TDHF level using various values of the CAP parameters r 0 and η. Simulations were performed for 5,000 a.u. of time propagation under a continuous wave and the HHG spectra are the same ones that are reported in Fig. , but are overlaid here with vertical lines representing the Koopmans' theorem IEs (-ε k where ε k is an occupied energy level, in translucent orange) and LR-TDHF excited states (in translucent green). Darker colored vertical lines indicate overlapping transitions in the stick spectra.