III. Total X‐ray Scattering and Two‐Electron Density Functions

Within the Waller–Hartree theory it is possible to map out the interelectron density function (the diagonal elements of the intracule matrix) from an analysis of total X‐ray scattering intensities. Theoretical studies of He and H2 show that electron correlation effects substantially influence total X‐ray scattering intensities, but do not appreciably alter the elastic X‐ray scattering intensity. On the other hand, theoretical studies of Be(1S), Ne(1S) and CO(1Σ*) indicate that electron correlation influences both total and elastic X‐ray scattering intensities by comparable amounts (∼ 1–2%), but at differing regions of the scattering vector variable.