NIR RSG model spectrum at 210 d with a NIR spectrum of Type IIP SN2017eaw taken at 215 d after explosion. The SN2017eaw spectrum is taken from Rho et al. (2018). The inset plot shows the CO first overtone emission band. The model overestimates the CO flux, especially in the higher excitation bandheads, despite containing less CO mass than was estimated for 2017eaw. Some discrepancy is expected from our assumption of LTE-level populations in CO. The model also significantly overestimates the strength of several Mg i lines in this region, suggesting that the model’s magnesium abundance may be much higher than SN2017eaw. The strength of the Mg i lines is slightly increased when CO is included, as a result of lower ionization in the CO-dominated regions.