Research output: Contribution to journal › Article › peer-review
The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18 : A novel interrupted silicate framework. / Li, Y.; Krivovichev, S. V.; Burns, P. C.
In: American Mineralogist, Vol. 85, No. 10, 2000, p. 1521-1525.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18
T2 - A novel interrupted silicate framework
AU - Li, Y.
AU - Krivovichev, S. V.
AU - Burns, P. C.
PY - 2000
Y1 - 2000
N2 - The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18, Z = 6, rhombohedral, a = 29.124(1), c = 17.2602(9) Å, V = 12,679.2(9) Å3, space group R3̄c, has been solved by direct methods, and refined to an agreement index (R1) of 5.7% calculated, based on 2266 unique observed reflections collected using MoKα X-radiation and a CCD-based detector. The structure consists of a new interrupted silicate framework with composition [Si8O19]6-. The framework density is 15.4 atoms per 1000 Å3, which is typical for microporous aluminosilicate materials. The framework density, together with the presence of a three-dimensional network of channels in the structure, permit thornasite to be designated as a new member of the zeolite structure family. The framework consists of cubic cages and distorted six-membered rings linked via common edges. The circuit symbol is (43143)(436214)3(6.10.12)3(6210)6. Interruptions of the framework are caused by the presence of Th4+ cations that are coordinated by eight O atoms. Na+ cations and H2O groups are located in channels through the structure. The theoretical parent framework for thornasite may be constructed by the insertion of two additional Si atoms in place of one Th atom. The theoretical framework density is 18.0 atoms per 1000 Å3; the circuit symbol is (43103)(436210)6(43628)3(436.8.10)3(42628.10)3(41638.10)3.
AB - The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18, Z = 6, rhombohedral, a = 29.124(1), c = 17.2602(9) Å, V = 12,679.2(9) Å3, space group R3̄c, has been solved by direct methods, and refined to an agreement index (R1) of 5.7% calculated, based on 2266 unique observed reflections collected using MoKα X-radiation and a CCD-based detector. The structure consists of a new interrupted silicate framework with composition [Si8O19]6-. The framework density is 15.4 atoms per 1000 Å3, which is typical for microporous aluminosilicate materials. The framework density, together with the presence of a three-dimensional network of channels in the structure, permit thornasite to be designated as a new member of the zeolite structure family. The framework consists of cubic cages and distorted six-membered rings linked via common edges. The circuit symbol is (43143)(436214)3(6.10.12)3(6210)6. Interruptions of the framework are caused by the presence of Th4+ cations that are coordinated by eight O atoms. Na+ cations and H2O groups are located in channels through the structure. The theoretical parent framework for thornasite may be constructed by the insertion of two additional Si atoms in place of one Th atom. The theoretical framework density is 18.0 atoms per 1000 Å3; the circuit symbol is (43103)(436210)6(43628)3(436.8.10)3(42628.10)3(41638.10)3.
UR - http://www.scopus.com/inward/record.url?scp=0033693015&partnerID=8YFLogxK
U2 - 10.2138/am-2000-1025
DO - 10.2138/am-2000-1025
M3 - Article
AN - SCOPUS:0033693015
VL - 85
SP - 1521
EP - 1525
JO - American Mineralogist
JF - American Mineralogist
SN - 0003-004X
IS - 10
ER -
ID: 88651507