THE ELECTRON-AFFINITY OF H-2 - A VALENCE BOND STUDY

A valence bond study of the potential energy curve for H + H- shows the system to be stable, against dissociation into H2 and a free electron, only for internuclear distances greater than 3.12a0. For shorter distances the energy curve shows a minimum at a bond length of about 1.5a0, but this represents a metastable tate embedded in the continuum of H2 plus a scattered electron. Electron impact experiments on hydrogen might be expected to reveal a Feshbach resonance at about 2.0eV.