Recent advances in coupled-cluster methods for the treatment of electron correlation in atoms (and molecules) have now made possible the computation of the ionization potentials and electron affinities of the atoms H through Ne with a mean absolute deviation of 0.35 meV with respect to experimental data. In this article, coupled-cluster wave functions are parametrized using orbital and Slater-type geminal basis functions. Many-body electron interactions are accounted for through connected quintuple excitations, and relativistic effects (spin-orbit as well as scalar) and diagonal Born-Oppenheimer corrections are included.

• Received 22 September 2009

DOI:https://doi.org/10.1103/PhysRevA.81.022503