Comparison of our modeling of ¹²CO⁺ spectrum with our observational data obtained on comet C/2016 R2 for different bands observed with the setting 437. The intensity scale is arbitrary but proportional to units of ergs s⁻¹ and is the same for the different bands. The observational spectrum appears in blue, while the modeling is in red. The emission lines of the (1,0) Π_1/2 band are mixed with the emission lines of the (4,2) Π_3/2 band, these last ones being fainter (intensities roughly equal to the ones of the (3,2) Π_3/2 band).