Use of local exchange potentials in the calculation of photoionization and electron-ion scattering

Several local approximations to exchange are investigated. These are compared against exact static-exchange results for e,Li+ scattering and for the photoionization of the 2S and 2P state of Li. All except one are found to be fairly accurate for these cases. Calculations are also performed for photoionization of the 5D state of Cs, which exhibits an f-wave resonance. All exchange models studied for this case (including the Slater Xα) are found to give widely differing results on the position and width of this resonance. Calculations are also performed for the photoionization of the Cs 6P state and compared against experimental results