Comparison between LTE and NLTE level and total number density. Top panel: departure coefficients for upper level of the transition A² ∆ with E = 3.2eV, J = 1.5, and υ = 1 and the lower level X²Π with E = 0.3 eV, J = 0.5, and υ = 1. The dashed black line indicates the departure coefficient for a thermalised level, for which holds true. Bottom panel: ratio of total CH number density in NLTE to the total CH number density in LTE.