An atlas of high resolution (⋋/Δ⋋=45,000) profiles of interstellar atomic lines of K I (7665, 7699 Å), Na I (D 1, D2), Ca II (H, K), Ca I (4227 Å), molecular structures of CH, CH+, CN and the major diffuse interstellar bands at 5780 and 5797 Å based on ~300 echelle spectra of ~200 OB stars is presented. Relationships between the reddenings, distances and equivalent widths of NaI, CaII, KI, CH, CH+, CN and diffuse bands are discussed. The equivalent width of K I (7699 Å) as well as of CH4300 Å' / correlate very tightly with E(B- V) in contrast to the features of neutral sodium, ionized calcium and the molecular ion CH+. The equivalent widths of the Hand K lines of Call grow with distance at a rate ~250mÅ per 1 kpc. A similar relation for NaI is much less tight. The strengths of neutral potassium lines, molecular features and diffuse interstellar bands do not correlate practically with distance. These facts suggest that ionized calcium fills the interstellar space quite homogeneously while the other carriers mentioned above, especially K I, CH and these of diffuse bands occupy more and more compact volumes, also filled with dust grains. Apparently the carriers of narrow diffuse bands are spatially correlated with simple molecules and dust grains - all abundant in the so-called 'zeta' type clouds. The same environment seems to be hostile to the carriers of broad diffuse interstellar bands (DIEs) (like 5780 or 6284) and -to a certain extent - also to CaII, NaI and CH+.