Relativistic effects in low energy electron scattering from atoms

Recent relativistic calculations on low energy elastic scattering of electrons from atoms are reviewed. Two aspects are emphasized : mathematical transformations and numerical methods used in the solution of the Dirac equation and the summation of the partial wave series ; and the results of relativistic calculations, in particular the behaviour of the cross sections and spin polarizations for different atoms, different energies of the incident electron, and in different approximations. The effects of the screening of the nucleus by the atomic electrons, electron exchange (including the use of approximate exchange potentials) and the distortion of the atom by the incident electron are discussed. Detailed results for cross sections and spin polarizations are given for mercury and the inert gases. The differences arising from use of the Dirac equation instead of the Schrödinger equation are considered.