Many-electron and orientation effects in anomalouselastic scattering of an x-ray photon by a linearmolecule

Abstract

A strong orientation effect is discovered theoretically upon thechange of the scheme of a suggested experiment on the anomalouselastic x-ray scattering of linearly polarized x-ray radiationby linear diatomics near the ionization thresholds of innermolecular orbitals. The effects on the shape oftheoretical scattering spectra of vibronic phenomena (for theHF and HCl molecules) are studied, as well as the additional excitation/ionizationof outer-shell electrons (the CO molecule). Within theone-centre approximation for the molecular orbitalwavefunctions the analytical structure of the linear molecule'sform factor is obtained. The calculation of one-electronwavefunctions is carried out with the inclusion of the effect ofcore relaxation in the field of the inner-shell vacancy withinthe one-centre method in the Hartree-Fock approximation. Thedipole transition matrix elements and photoabsorption crosssections are calculated by the methods of the theory ofnon-orthogonal orbitals.