Cross-correlated templates showing molecular harmonics and symmetric patterns for H₂O and CO. Left: Cross-correlation of templates with themselves (with T_eff = 1200 and log(g) = 4.1),allowing to verify how the molecular harmonics behave for H₂O and CO. The cross-correlation shows clear symmetric patterns for both molecules and strong harmonic patterns for CO. Right: Cross-correlation of different templates with each other, i.e. one template of template of T_eff = 1200 and log(g) = 4.1 and one template of T_eff = 2200 and log(g) = 4.1 as shown in the right panel.