Configuration interaction calculations of positronic atoms and ions

The configuration interaction (CI) method is one of the most commonly used methods for the calculation of the electronic structure of atoms. The standard CI method based on a linear combination of orthonormal orbitals centered on the nucleus has been adapted to the calculation of the structure of exotic atoms containing one or two electrons and a positron. Results of calculations on a number of systems, including positronium hydride (PsH), e⁺Cu, e⁺Li, e⁺Be, e⁺Cd and CuPs show both the strengths and limitations of the CI approach for positron binding atoms.