TY - JOUR

T1 - Crystal structure of γ-Cu2V2O7 and its comparison to blossite (α-Cu2V2O7) and ziesite (β-Cu2V2O7)

AU - Krivovichev, Sergey V.

AU - Filatov, Stanislav K.

AU - Cherepansky, Pavel N.

AU - Armbruster, Thomas

AU - Pankratova, Olga Yu

PY - 2005/4

Y1 - 2005/4

N2 - Single crystals of-γ-Cu2V2O7 were obtained by the method of chemical transport reactions. The crystal structure [triclinic, Pl̄, a 5.0873(10), b 5.8233(11), c 9.4020(18) Å. α 99.780(3), β 97.253(3), γ 97.202(3)°, V 269.20(9) Å3, Z = 2] has been solved by direct methods and refined to R1 = 0.021 (wR2, = 0.049) using 949 unique observed reflections with Fo ≥ 4σF. The atomic arrangement contains two symmetrically independent Cu2+ cations. The Cu(1) site is coordinated by six O atoms to form a distorted Cu(1)O6 octahedron, whereas the Cu(2) site is coordinated by five O atoms arranged at the vertices of an elongate Cu(2)O5 square pyramid. Two symmetrically independent V5+ cations are tetrahedrally coordinated by four O atoms each. The O(5) atom bridges the V(1)O4 and V(2)O4 tetrahedra. The Cu(1)O6 octahedra and Cu(2)O5 square pyramids form two types of chains running parallel to the a axis. The chains are linked by V2O7 groups into a complex heteropolyhedral framework. The structure of γ-Cu2V2O7 is closely related to the structures of α-Cu2V2O7 (blossite) and β-Cu2V2O7 (ziesite). The three structures are based upon chains of edge-sharing Cu2+ polyhedra linked by V2O7 groups. Similarity of the structure of γ-Cu2V2O7 to the structures of blossite and ziesite indicates possible formation of this phase under natural conditions, such as those that occur in "dry" high-temperature fumaroles of the Izalco (El Salvador) and Tolbachik (Kamchatka, Russia) volcanoes. The structure of γ-Cu2V2O7 can also be considered as a triclinically distorted derivative of the β-A2P2O7 structure-type.

AB - Single crystals of-γ-Cu2V2O7 were obtained by the method of chemical transport reactions. The crystal structure [triclinic, Pl̄, a 5.0873(10), b 5.8233(11), c 9.4020(18) Å. α 99.780(3), β 97.253(3), γ 97.202(3)°, V 269.20(9) Å3, Z = 2] has been solved by direct methods and refined to R1 = 0.021 (wR2, = 0.049) using 949 unique observed reflections with Fo ≥ 4σF. The atomic arrangement contains two symmetrically independent Cu2+ cations. The Cu(1) site is coordinated by six O atoms to form a distorted Cu(1)O6 octahedron, whereas the Cu(2) site is coordinated by five O atoms arranged at the vertices of an elongate Cu(2)O5 square pyramid. Two symmetrically independent V5+ cations are tetrahedrally coordinated by four O atoms each. The O(5) atom bridges the V(1)O4 and V(2)O4 tetrahedra. The Cu(1)O6 octahedra and Cu(2)O5 square pyramids form two types of chains running parallel to the a axis. The chains are linked by V2O7 groups into a complex heteropolyhedral framework. The structure of γ-Cu2V2O7 is closely related to the structures of α-Cu2V2O7 (blossite) and β-Cu2V2O7 (ziesite). The three structures are based upon chains of edge-sharing Cu2+ polyhedra linked by V2O7 groups. Similarity of the structure of γ-Cu2V2O7 to the structures of blossite and ziesite indicates possible formation of this phase under natural conditions, such as those that occur in "dry" high-temperature fumaroles of the Izalco (El Salvador) and Tolbachik (Kamchatka, Russia) volcanoes. The structure of γ-Cu2V2O7 can also be considered as a triclinically distorted derivative of the β-A2P2O7 structure-type.

KW - Blossite

KW - Crystal structure

KW - Fumarole

KW - Ziesite

KW - γ-CuVO

UR - http://www.scopus.com/inward/record.url?scp=21944442297&partnerID=8YFLogxK

U2 - 10.2113/gscanmin.43.2.671

DO - 10.2113/gscanmin.43.2.671

M3 - Article

VL - 43

SP - 671

EP - 677

JO - Canadian Mineralogist

JF - Canadian Mineralogist

SN - 0008-4476

IS - 2

ER -