Heavy Rydberg behaviour and absolute quantum defects are reported for resonances in the ungerade manifold of H-2 above the (1s,3l ) dissociation limit. The continuity of the vibrational progression of the B ''(B) over bar state through the crossing with the 3p asymptote is demonstrated and a predominantly diabatic picture of the vibrational motion emerges, indicating that the ion-pair resonances possess little 6(1)Sigma(+)(u) state character. (C) 2017 Elsevier B.V. All rights reserved.