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Titolo:
O-D center dot center dot center dot O bond geometry OD-chondrodite
Autore:
Lager, GA; Ulmer, P; Miletich, R; Marshall, WG;
Indirizzi:
Univ Louisville, Dept Geog & Geosci, Louisville, KY 40292 USA Univ Louisville Louisville KY USA 40292 Geosci, Louisville, KY 40292 USA Swiss Fed Inst Technol, Inst Mineral & Petrog, CH-8092 Zurich, SwitzerlandSwiss Fed Inst Technol Zurich Switzerland CH-8092 92 Zurich, Switzerland Swiss Fed Inst Technol, Crystallog Lab, CH-8092 Zurich, Switzerland Swiss Fed Inst Technol Zurich Switzerland CH-8092 92 Zurich, Switzerland Rutherford Appleton Lab, CLRC, ISIS Facil, Didcot OX11 0QX, Oxon, England Rutherford Appleton Lab Didcot Oxon England OX11 0QX 1 0QX, Oxon, England
Titolo Testata:
AMERICAN MINERALOGIST
fascicolo: 1-2, volume: 86, anno: 2001,
pagine: 176 - 180
SICI:
0003-004X(200101/02)86:1-2<176:OCDCDC>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROUS MAGNESIUM SILICATES; HIGH-PRESSURE; SYSTEM MGO-SIO2-H2O; VIBRATIONAL-SPECTRA; CRYSTAL-STRUCTURES; HUMITE MINERALS; UPPER-MANTLE; CLINOHUMITE; DIFFRACTION; STABILITY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
48
Recensione:
Indirizzi per estratti:
Indirizzo: Lager, GA Univ Louisville, Dept Geog & Geosci, Louisville, KY 40292 USA Univ Louisville Louisville KY USA 40292 ouisville, KY 40292 USA
Citazione:
G.A. Lager et al., "O-D center dot center dot center dot O bond geometry OD-chondrodite", AM MINERAL, 86(1-2), 2001, pp. 176-180

Abstract

The crystal structure of OD-chondrodite {Mg5Si2O8(OD)(2), P2(1)/b (a unique), a = 4.74711(5), b = 10.34888(16), c = 7.90228(13) Angstrom, alpha = 108.678(1)degrees] was refined to wR(p) = 0.0218, chi (2) = 3.545 at ambient conditions using time-of-flight neutron powder data. The disordered H model proposed for OH-chondrodite on the basis of single-crystal X-ray data is confirmed. The occupations of the D1 and D2 sites are, respectively, 0.52(1) and 0.48(1). The long O5-D1 [1.076(4) Angstrom] and O5-D2 [1.111(4) Angstrom] bond lengths, which are two of the longest O-H(D) bonds observed in mineral structures, reflect the positional disorder of the O5 atom in the unshared OH-OH-edge. Both D1 [1.968(4), 2.489(4) Angstrom] and D2 [2.149(4), 2.251(4) Angstrom] atoms are involved in two hydrogen bonds. A re-examination of the origin of positive OH frequency shifts in both F-bearing and OH-clnondrodite at high pressure is warranted in View of the crystallographic data.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 13/07/20 alle ore 11:02:56