Relativistic configuration-interaction calculations for atoms with one valence electron based on altering hydrogenlike or Dirac-Fock spin orbitals

Relativistic configuration-interaction calculations using hydrogenlike or Dirac-Fock spin orbitals of the transition from the ground state to some np(1/2), np(3/2) low-lying excited states for the alkali metals are presented. In these calculations each virtual spin orbital corresponds to a unique noninteger atomic number determined iteratively using the virtual-particle model. The virtual-particle model based on "condensed-space" idea is here adopted to many electron systems consisting of a single valence electron and the core. The transition energy and the oscillator strength values were computed for sodium, potassium, rubidium, cesium, and francium. Both hydrogenlike and Dirac-Fock basis functions have been used in the computations for comparison.