The effect of configuration-interaction target states on the elastic scattering of low-energy electrons by complex atoms

Abstract

The total wavefunction (target plus incident electron) is represented by a close-coupling expansion. For complex atoms such as atomic helium and oxygen, the effects of configuration-interaction target states are discussed and analysed, in part. For atomic helium, the ²S partial-wave elastic cross section obtained using a He configuration-interaction ground state is virtually identical with the corresponding cross section obtained using a Roothaan-Hartree-Fock ground state. For atomic oxygen, the ⁴P partial-wave elastic phaseshift can increase to such an extent as to cause the ⁴P partial-wave cross section to go through zero at k² approximately=0.2 Ryd. Finally, a second procedure is discussed for including correlation states when CI target states are used in the close-coupling expansion.