W(CH) (top) and W(CH⁺) (bottom) versus W_λ(5780). The λ5780 DIB shows no direct correlation with either CH or CH⁺. Looking separately at the σ and ζ-type sightlines one can distinguish different behaviour between the molecular lines and the λ5780 DIB for both types. Sightlines classified as intermediate are indicated by green crosses. DIBs are stronger with respect to CH and CH⁺ line strengths for σ-type sightlines. In other words, the 5780 DIB carrier abundance is lower for ζ-type clouds which have a higher molecular content.