title: Biaxial tensors for anomalous scattering of X-rays in selenolanthionine.
abstract: X-ray pleochroism is observed near the Se K absorption edge in a monoclinic crystal of selenolanthionine monohydrate using linearly polarized synchrotron radiation and is explained by a simple molecular-orbital model. The complex anomalous-scattering tensor of selenium, measured by diffraction in a tetraronal crystal of the anhydrous compound, exhibits anisotropy nearly 6 for f' and 7 for f", the most yet found for a K edge. The crystal structure was determined for D-(-)-selenolanthionine, space group P4(3)2(1)2, a = 6.651 (2), c = 21.758 (5) A, Z = 4, R = 0.027 for 304 unique reflections.
authors.affiliation: Department of Chemistry, University of California, Berkeley 94720.
authors.forename: L K
authors.initials: LK
authors.lastname: Templeton
authors.forename: D H
authors.initials: DH
authors.lastname: Templeton
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives*; D008968:Molecular Conformation; D016566:Organoselenium Compounds; D012542:Scattering, Radiation; D012643:Selenium; D013050:Spectrometry, Fluorescence; D014961:X-Ray Diffraction
chemical_list: D016566:Organoselenium Compounds; C062653:selenolanthionine; D012643:Selenium; D000409:Alanine