TY - JOUR

T1 - The crystal structure of kukharenkoite-(Ce), Ba2REE(CO3)3F, and an interpretation based on cation-coordinated F tetrahedra

AU - Krivovichev, Sergey V.

AU - Filatov, Stanislav K.

AU - Zaitsev, Anatoly N.

PY - 1998/6/1

Y1 - 1998/6/1

N2 - The crystal structure of kukharenkoite-(Ce), Ba2REE(CO3)3F, from the Khibina carbonatite, Kola Peninsula, Russia, has been refined to R = 0.044 (wR = 0.112) using 2296 reflections. The mineral is monoclinic, space group P21/m, with a 13.374(3), b 5.1011(8), c 6.653(1) Å, ß 106.56(1)°, V 435.1(1) Å3, Z = 2. The structure is similar to that determined by Mercier & Leblanc (1993) for synthetic Ba2Ce(CO3)3F. The F- anion is tetrahedrally coordinated by three Ba and one Ce cations. F-centered [FCeBa3] tetrahedra are linked through shared edges to form double chains {uB, 2∞1}[FCeBa] along the b axis. C(3)O3 carbonate groups are positioned on the faces of the [FCeBa3] tetrahedra, resulting in complex [FCeBa](CO3) chains. These chains are positioned in sheets parallel to (001) (layer A) and alternating along [001] with sheets formed by C(1)O3 and C(2)O3 groups and Ba atoms that do not bond with fluorine (layer B). The structures of other fluorocarbonates with fluorine-centered tetrahedra contain the following tetrahedral complexes: double chains {uB, 2∞1} [F2M5] in cebaite-(Ce), Ba3Ce2(CO3)5F2, and Ba3La2(CO3)5F2, layers {uB, 1∞2}[F2M3] in huanghoite-(Ce), BaCe(CO3)2F, and BaSm(CO3)2F, layers {uB, 1∞2}[FM] in kettnerite, CaBiOF(CO3), frameworks {∞3}[FM] in brenkite, Ca2F2(CO3), and Pb2F2(CO3), frameworks {∞3}[FM] in BaCu(CO3)F2, and frameworks {∞3}[FM4] in horváthite-(Y), NaY(CO3)F2. Topologically similar structural units composed of [OM4] tetrahedra have been described in oxysalts with "additional" oxygen atoms.

AB - The crystal structure of kukharenkoite-(Ce), Ba2REE(CO3)3F, from the Khibina carbonatite, Kola Peninsula, Russia, has been refined to R = 0.044 (wR = 0.112) using 2296 reflections. The mineral is monoclinic, space group P21/m, with a 13.374(3), b 5.1011(8), c 6.653(1) Å, ß 106.56(1)°, V 435.1(1) Å3, Z = 2. The structure is similar to that determined by Mercier & Leblanc (1993) for synthetic Ba2Ce(CO3)3F. The F- anion is tetrahedrally coordinated by three Ba and one Ce cations. F-centered [FCeBa3] tetrahedra are linked through shared edges to form double chains {uB, 2∞1}[FCeBa] along the b axis. C(3)O3 carbonate groups are positioned on the faces of the [FCeBa3] tetrahedra, resulting in complex [FCeBa](CO3) chains. These chains are positioned in sheets parallel to (001) (layer A) and alternating along [001] with sheets formed by C(1)O3 and C(2)O3 groups and Ba atoms that do not bond with fluorine (layer B). The structures of other fluorocarbonates with fluorine-centered tetrahedra contain the following tetrahedral complexes: double chains {uB, 2∞1} [F2M5] in cebaite-(Ce), Ba3Ce2(CO3)5F2, and Ba3La2(CO3)5F2, layers {uB, 1∞2}[F2M3] in huanghoite-(Ce), BaCe(CO3)2F, and BaSm(CO3)2F, layers {uB, 1∞2}[FM] in kettnerite, CaBiOF(CO3), frameworks {∞3}[FM] in brenkite, Ca2F2(CO3), and Pb2F2(CO3), frameworks {∞3}[FM] in BaCu(CO3)F2, and frameworks {∞3}[FM4] in horváthite-(Y), NaY(CO3)F2. Topologically similar structural units composed of [OM4] tetrahedra have been described in oxysalts with "additional" oxygen atoms.

KW - Crystal structure

KW - Fluorine-centered tetrahedra

KW - Fluorocarbonate

KW - Khibina

KW - Kukharenkoite-(Ce)

UR - http://www.scopus.com/inward/record.url?scp=0032458667&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032458667

VL - 36

SP - 809

EP - 815

JO - Canadian Mineralogist

JF - Canadian Mineralogist

SN - 0008-4476

IS - 3

ER -