title: Phase measurement for accurate mapping of chemical bonds in acentric space groups.
abstract: Although the electron density is fundamental to the study of chemical bonding and density-functional theory, it cannot be accurately mapped experimentally for the important class of crystals lacking inversion symmetry, since structure factor phase information is normally inaccessible. We report the combination of x-ray and electron diffraction experiments for the determination of the electron density in acentric AlN, using multiple-scattering effects in convergent-beam electron diffraction to obtain sensitivity to structure factor phases, and describe a new error metric and weighting scheme for multipole refinement using combined measurements of structure factor magnitudes and phases.
authors.affiliation: John Cowley EM Center, ASU, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Spackman
authors.forename: B
authors.initials: B
authors.lastname: Jiang
authors.forename: T L
authors.initials: TL
authors.lastname: Groy
authors.forename: H
authors.initials: H
authors.lastname: He
authors.forename: A E
authors.initials: AE
authors.lastname: Whitten
authors.forename: J C H
authors.initials: JC
authors.lastname: Spence