| Popis: |
Zoltaiite, ideal formula BaV2 4+ V 3+ 3+ 11.06Fe 3+ 0.49Cr0.34)Σ11.89Si2.06O27 based on O = 27. The crystal structure was solved by direct methods and reÞ ned on the basis of F0 2 using all unique res ections measured with MoKα X- radiation on a CCD-equipped diffractometer. The Þ nal R factor was 3.2%, calculated using 659 unique observed res ections. The unit cell contains four layers of two types parallel to (001): X, an octahedral and tetrahedral sheet, and Y, an octahedral plus barium sheet; both layers are doubled through inversion centers resulting in the sequence XXYY... Two consecutive equivalent layers are interconnected through shared octahedral edges, whereas consecutive non-equivalent layers are linked through shared corners. The high calculated density is consistent with the dense packing of the structure. |
