Autodetachment phenomena at high internuclear separation for some H2-resonances

Using a very sensitive electron impact spectrometer it has been possible to observe the autodetachment of some H 2 - states at large internuclear separation which, under certain conditions, corresponds to a dissociation into unstable H - (2l2l') followed by autodetachment yielding H(1s)+e. The existence of the b 2 Sigma g + resonance is confirmed. A correlation diagram is proposed: the a 2 Sigma g + state dissociates to H - (2s 2 1 S e )+H(1s), c 2 Pi u to H (2s2p 3 P 0 )+H(1s) and D 2 Delta g to H - (2p 2 1 D e )+H(1s).