Accuracy of pseudostates for the electron-hydrogen scattering problem

Abstract

The accuracy of several pseudostate basis sets for calculating second-order amplitudes is determined by comparing second-order distorted-wave amplitudes calculated using pseudostates with recent exact results. The accuracy of both the total basis sets and individual s-, p- and d-state components of the basis sets is determined and improved basis sets are formed by combining the best s-, p- and d-state basis sets. Both the improved basis sets and the original basis sets are used to calculate physically measurable quantities and the errors for the various pseudostates are determined. The primary objective for the study is to find an accurate pseudostate basis set which may be used in a close-coupling calculation since this method shows the most promise for obtaining accurate cross sections. The question of whether the pseudostate basis sets found in the paper which give accurate DWB2 results for excitation of the 2p state of hydrogen may also be used in a close-coupling calculation with comparable accuracy is addressed.