Coulomb hole in N2, CO and O2 deduced from X-ray scattering cross-sections

摘要: Accurate total (elastic  and  inelastic) X-ray scattering cross-sections of N2, CO O2 were measured by the use energy dispersive method up to a momentum transfer q = 12 au. The radial electron pair distribution function P(r 12) was extracted from cross-sections. Coulomb hole, defined as difference between exact corresponding evaluated at Hartree–Fock limit, has been derived experimental data for first time. Comparison multi-reference configuration interaction (MRCI) averaged quadratic coupled cluster (MR-AQCC) calculations indicates substantial shortcomings MRCI due lack size extensivity. overall agreement with experiment is good but some differences theoretical results remain.