Numerical multiconfiguration self-consistent-field studies of atomic photoionization cross sections: Dynamical core-polarization effects in atomic potassium

The numerical multiconfiguration self-consistent-field method is used to calculate photoionization cross sections of atomic potassium in its ground state for photoelectron energies ranging from 0.0 to 12 eV. The effects of core polarization, which are very important for this atom, are analyzed in detail and are taken into account effectively ab initio in both the initial and the final state, by the configuration-interaction procedure. It is found that the core-polarization effect is very strong in the photoionization cross section of potassium. Our results are found to be in good agreement with previous theoretical calculations throughout the energy region considered and also with experiment except at high energies.