title: Structures of the pseudo-trigonal polymorphs of Cu2(OH)(3)Cl.
abstract: The crystal structure of Cu2(OH)(3)Cl has been determined using two natural samples with almost ideal stoichiometry. While one of the samples exhibits a twinned clinoatacamite structure, the other sample is characterized by the appearance of additional weak diffraction maxima at half integer positions of h and k. Structure refinement was carried out with the space group P1. The relationship between the triclinic phase, clinoatacamite, paratacamite and the herbertsmithite structure is discussed in terms of symmetry as a function of Cu concentration.
authors.affiliation: Mineralogisch-Petrographisches Institut, Universität Hamburg, Grindelallee 48, D-20146 Hamburg, Germany. thomas.malcherek@uni-hamburg.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Malcherek
authors.forename: Jochen
authors.initials: J
authors.lastname: Schlüter