Mid-IR AKARI spectrum reported by Rho et al. (2012) for knot n2 in Cas A is compared with models that have been convolved to the same resolution, 0.1125 μm. The black curve is the observed spectrum. The red curve is the computed spectrum for the same two-component non-LTE model that best describes the fluxes of the CO rotational lines, but scaled in intensity by a factor 1/16. The cyan curve represents the vibrational emission expected in strict LTE for the column density and temperature derived from the rotation diagram in Fig. 3, but scaled down by a factor of 10^-4. The computed spectra include more than 4000 vibration-rotation lines, each of which has a width of 415 km s^-1.