Ceramics-Silikáty 25, (2) 113 - 116 (1981) |
|
THE CRYSTAL STRUCTURE OF Ca₃(CrO₄)₂
|
Gyepesová Dalma, Handlovič Milan, Ďurovič Slavomil
|
Institute of Inorganic Chemistry, Slovak. Academy of Sciences, 809 34 Bratislava, Dúbravská cesta 5
|
Ca₃(CrO₄)₂ crystallizes in the trigonal space group R3c. The lattice parameters in the rhombohedral (R) and in the corresponding hexagonal (H) description are as follows: aR = 1.4148(3) nm, α = 44.77(1)°, ZR = 7 and aH = 1.0776(2) nm, cH = 3.8119(5) nm, ZH = 21. Ca₃(CrO₄)₂ is isostructural with Ca₃(VO₄)₂, Ca₃(AsO₄)₂ and β Ca₃(PO₄)₂ . The structure was refined (isotropic temperature factors, 1749 independent difractions) up to R = 0.087. The Ca atoms are coordinated by 6, 7 or 8 oxygen atoms. The coordination of Cr is tetrahedral. |
 PDF (0.4 MB) |
|
