Electron-impact double ionization of H-

Electron-impact double ionization cross sections for H- are calculated using a non-perturbative time-dependent close-coupling theory. The total wavefunction for the three-electron system is represented by a coupled channels expansion involving simple products of three-dimensional radial lattices and six-dimensional coupled spherical harmonics. Following time evolution of the total wavefunction according to the Schrodinger equation, collision probabilities are found by projection of the total wavefunction onto fully antisymmetric products of spatial and spin functions representing three outgoing Coulomb waves. The completely ab initio double ionization cross section results for H- are found to be more than a factor of 5 below the experimental measurements of Peart et al (1971 J. Phys. B: At. Mol. Phys. 4 88) and in excellent agreement with the experimental measurements of Yu et al (1992 J. Phys. B: At. Mol. Opt. Phys. 25 4593).