학술논문
Refinement of the crystal structure of berezanskite, Ti2 □2 KLi3 (Si12 O30 ).
Document Type
Article
Source
Subject
*CRYSTAL structure
*MINERALOGY
*SPACE groups
*TITANIUM compounds
*SILICON
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Language
ISSN
0026-461X
Abstract
Berezanskite, ideally Ti2□2KLi3(Si12O30), is hexagonal, space group P6/mcc, a=9.898(4), c=14.276(6) Å, V=1211.2(9) ų, Z=2. The crystal structure was refined to an R1 index of 2.08% based on 392 unique observed reflections. Berezanskite is isostructural with milarite, ideally ACa2BoCKT(2)(Be2Al)(T(1)Si12O30)(H2O)0-2. The structural unit is of the form [T(2)3T(1)12O30] with T(1)=Si and T(2)=Li, in which (LiO4) tetrahedra link [Si12O30] six-membered double-rings into a framework. The A, B and C sites occur in the interstices of the framework with the following site populations: A=Ti4+2, =1.938(2) Å; B=□2; C=K, =3.058(2) Å. In the T(2)=Li3 milarite-group minerals, the distance is inversely related to the occupancy of the B site. [ABSTRACT FROM AUTHOR]