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The conversion of quantum electrodynamics to a configuration-space Hamiltonian formalism introduces three-electron potentials of relativistic origin. For heavy atoms, it is found that the contribution of these potentials to the inner-shell binding energy is no more than 0.21 eV. This is too small to explain the discrepancy between current theory and experiment. The uniqueness of the potentials obtained in the configuration-space Hamiltonian is also discussed.

The modification of the photoionization cross section due to the presence of an intense low-frequency laser is obtained for the hydrogen-atom target. Previous calculations of this effect have neglected the effects of the Coulomb potential in the final state. A sum rule was obtained which indicates that the photoelectric current is unaffected by the presence of the low-frequency laser to lowest order in the laser frequency. It is found that the Coulomb potential changes this result and that the photoelectric current is changed by a factor which depends upon the laser parameters and the electron momentum. A simple experiment is suggested to confirm this prediction.

When an electron scatters from an atom in the presence of a laser field which is resonant with an atomic transition, off-shell effects enter into the cross section. These only become significant at higher laser intensities where the atom may also be ionised by the laser. Cross-sections are obtained for electron-atom scattering in which these off-shell effects appear and in which the slow ionisation of the atom by the laser is included. Experiments are suggested in which simplifications can occur and which still retain these 'exotic' effects.

Positronium formation in positron-helium scattering, including polarizability in potentials appearing in final equations

Polar molecule rotational excitation diffusion cross sections for electron scattering

Dissociative attachment and recombination, discussing resonance state joining and asymptotic physical state and projection operator techniques

Polarized orbital method for calculating electron-atom scattering amplitudes, noting discontinuous wave function, nonvariational technique and strong dependence on parameter

Single photon excitation of two ground state atoms in collision, estimating absorption coefficient of He

Polarization of He atomic radiation excited by electron impact at threshold energy, discussing deviations from theory

High energy charge transfer one dimensional model solved numerically and compared to approximations, noting proton-H collisions and atomic excitation by protons

Pure rearrangement collisions in excitation of triplet helium states by electrons, discussing relativistic contributions to cross section

Positronium formation in positron-hydrogen scattering solved by coupled equations

Fermi pressure shifts of highly excited states of atoms in gaseous medium due to electron particle interactions, discussing scattering contributions

Resonances in proton hydrogen and positron hydrogen scattering predicted at energies just below excitation thresholds

High energy rearrangement collision in which fast proton incident upon atom picks up electron