PDLAs in our sample ordered according to the velocity difference between the centroid of the neutral gas (estimated from z₅₀) and the systemic redshift of the quasar from optical emission lines. The dashed-dotted lines shows the typical velocity shift of the CO(3–2) emission in six systems observed with NOEMA, which may, on average, represent a better measurement of systemic redshift. The gray rectangles depict the low-ionization Δv₉₀ range. Red crosses represent the position of H₂ components. Diamonds represent N V components, colored according to the derived ionization parameter.