ELASTIC-SCATTERING OF ELECTRONS AND POSITRONS BY ATOMS - SCHRODINGER AND DIRAC PARTIAL-WAVE ANALYSIS

Two FORTRAN 77 codes are described which provide a complete description of elastic scattering of electrons and positrons by atoms using the static field approximation with non-relativistic (Schrodinger) and relativistic (Dirac) partial wave analysis. The delivered information includes phase shifts, differential cross-sections, scattering amplitudes and percentage points of the single scattering angular distribution. The scattering field may be internally generated by the codes (which incorporate an accurate analytical approximation to the Dirac-Hartree-Fock-Slater field of free atoms) or read from the input file. Solid state effects for scattering in solids are described by means of a simple muffin-tin model. For electron scattering, exchange corrections are also taken into account. Phase shifts are obtained by using the RADWEQ subroutine package [Comput. Phys. Commun. 62 (1991) 65] to solve the radial equations. The relativistic code provides reliable cross-section data for kinetic energies between approximately 1 keV and approximately 1 MeV.