Observed products of H + HNCO in the multilayer regime. In the left panel, the spectra are as follows: a) the new band at 1680 cm^-1 (magnification of the difference spectrum in Fig. 1c; b) a spectrum of pure H₂O, scaled to the band at 1680 cm^-1 (magnification of Fig. 1d); and c) a spectrum of pure NH₂CHO, scaled to the band at 1680 cm^-1. In the right panel, the spectra are the difference spectra of H-bombarded HNCO and pure HNCO are shown for bombardment times of d) 20 min; e) 80 min; and f) 140 min (magnification of the difference spectrum in Fig. 1c.