Russian Mineralogical Society
200th Anniversary Meeting of the Russian Mineralogical Society
Fivefold coordinated silicon in the crystal structure of high-pressure modification of datolite CaBSiO4(OH)

RMS-DPI code:  2017-1-33-0
Scientific session:  2. Mineralogical crystallography and crystal chemistry.
Author listing:  Gorelova L., Pakhomova A.S., Krivovichev S.V., Dubrovinsky L., Aprillis G.
Principal author:  Gorelova Liudmila
Language:  Russian
Abstract - Summary 
(short description):
High-pressure (043 GPa) single-crystal X-ray diffraction experiments were conducted on natural datolite CaBSiO4(OH). We observe polymorphic transition between 27 and 33 GPa into the high-pressure phase. The high pressure crystal structure of datolite contains Si atoms coordinated by five oxygen atoms to form a trigonal bipyramid SiO5. As a result of phase transition, two SiO4 tetrahedra across the eight-membered ring of the borosilicate layer approach each other and form dimers of edge-sharing SiO5 bipyramids. The structure symmetry (P21/c) remains unchanged.
RMS-DPI code:  2017-1-33-0
Pages:  37-38
File of proceedings 
 115 K
Status:  printed
Accepted:  15/09/2017
Published on-line:  06/12/2017
Permanent address of publication:
Contact author(s):  Gorelova, Liudmila

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