We present calculation of the 4d-4f energy separation in Li I using two advanced teqhniques in atomic structure theory, namely, relativistic all-order method and multiconfiguration Hartree-Fock (MCHF) method. The accuracy of our calculations is also investigated by conducting a third-order many-body perturbation theory (MBPT) calculation that allowed us to evaluate the importance of fourth and higher-order corrections. A large-scale MCHF calculation is performed using the active space method and the core-polarization approximation. The obtained results are shown to agree with the most accurate available experimental data.
Citation: Physical Review A (Atomic, Molecular and Optical Physics)
Pub Type: Journals
energy levels, hartee-fock, neutral lithium, pertubation theory