The polarized frozen core approximation: Energies and oscillator strengths of C(I) and N(II)

The frozen core and extended frozen core versions of the Hartree-Fock approximation have been improved significantly by means of l-dependent core polarization potentials. The resulting polarized frozen core procedure reproduces most of the observed 2pns, 2pnp and 2pnd terms of C(I) and N(II) with great accuracy; over 60 unobserved terms in N(II) have been calculated, which should prove sufficiently reliable for future identification purposes. Length and velocity forms of electric dipole oscillator strenghts, calculated with these polarized orbitals and the corresponding energies, are generally in excellent agreement, particularly for transitions between the more highly excited states.