Relativistic Convergent Close-coupling Research Articles

Relativistic convergent close-coupling method: Calculations of electron scattering from cesium

We present a detailed formulation of the relativistic convergent close-coupling (RCCC) method which is based on the solution of the Dirac equation describing electron scattering from quasi-one-electron atoms. A square-integrable Dirac $L$ spinor basis has been used to obtain a set of target states representing both the bound and continuum spectra of the target. A set of momentum-space coupled Lippmann-Schwinger equations for the $T$ matrix is then formulated and solved. We use spin asymmetries, particularly those that are identically zero in a nonrelativistic formulation, to check the accuracy of the RCCC method and find good agreement with experiment on a broad energy range.

Fully Relativistic Convergent Close-Coupling Method for Excitation and Ionization Processes in Electron Collisions with Atoms and Ions

We report the development of the fully relativistic convergent close-coupling method based on the solution of the Dirac equation. A complete square-integrable Dirac L-spinor basis is used to obtain a set of target states spanning the target discrete and continuous positive- and negative-energy spectra. The present implementation is for quasi-one-electron atoms whose electronic configuration corresponds to the first column of the periodic table. By way of example, we consider elastic scattering of 7 eV electrons on the ground state of cesium, where the full set of spin asymmetries (A1, A2, Ann) has been measured. Excellent agreement with experiment is found.