Titre du document / Document title

Crystal structure of paralaurionite and its OD relationships with laurionite

Auteur(s) / Author(s)

MERLINO S. ; PASERO M. ; PERCHIAZZI N. ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

Univ. Pisa, dip. sci. Terra, 56126 Pisa, ITALIE

Résumé / Abstract

The crystal structure of the rare lead hydroxychloride paralaurionite [PbCl(OH), monoclinic, space group C2/m, a = 10.865(4), b = 4.006(2), c = 7.233(3) Å, β = 117.24(4)°] has been refined to R = 0.062, R_w = 0.048. Its Order-Disorder (OD) character and its OD relationships with the orthorhombic polytpe of PbCl(OH), laurionite, are discussed. Laurionite and paralaurionite represent the two MDO structures within a family of OD structures built up by two different kinds of layers. The structures of paralaurionite and laurionite are compared thoroughly. The first coordination of the various atoms in the two polytypes is the same, however, remarkable differences exist in the connection between adjacent Pb-centred polyhedra

Revue / Journal Title

Mineralogical Magazine   ISSN 0026-461X   CODEN MNLMBB 

Source / Source

1993, vol. 57, n^o2, pp. 323-328 (27 ref.)

Langue / Language

Anglais

Editeur / Publisher

Mineralogical Society, London, ROYAUME-UNI  (1969) (Revue)

Mots-clés anglais / English Keywords

laurionite ; paralaurionite ; chlorides ; crystal structure ; symmetry ; space groups ; unit cell ; cell dimensions ; order-disorder ; polytypism ; coordination ; atomic packing ; Tuscany ; X-ray diffraction analysis ; bonding ; Italy ; Europe ;

Mots-clés français / French Keywords

Laurionite ; Paralaurionite ; Chlorure ; Structure cristalline ; Symétrie ; Groupe espace ; Maille élémentaire ; Constante réticulaire ; Ordre désordre ; Polytypisme ; Coordinence ; Empilement atome ; Toscane ; Diffraction RX ; Liaison interatomique ; Hydroxychlorure ; Italie ; Europe ;

Mots-clés espagnols / Spanish Keywords

Laurionita ; Paralaurionita ; Cloruro ; Estructura cristalina ; Simetría ; Grupo espacio ; Celdilla cristalina ; Constante reticular ; Orden desorden ; Politipismo ; Coordinancia ; Estructura átomo ; Toscana ; Difracción RX ; Enlace interatómico ; Italia ; Europa ;

Localisation / Location

INIST-CNRS, Cote INIST : 3052, 35400003396075.0150