五磷酸铈的晶体结构

五磷酸铈晶体的分子式为CeP₅O₁₄,属单斜晶系,α=8.797?, b=9.074?,c=13.124?,β=89°36′,Z=4,空间群C_2h⁵-P₂₁/c,用PW-1100四圆衍射仪收集强度数据,独立衍射点2051个,结构已用重原子法解出,以全矩阵及方块矩阵最小二乘方修正结构参数,最后R因子为0.097。晶体结构分析结果表明,结构系由阳离子连结阴离子带构成络合物,围绕着铈离子的八个氧原子构成稍歪扭的“正方”反三稜形配位多面体,两个Ce离子间的最短距离为5.967?。关键词：

CRYSTAL STRUCTURE OF CERIUM PENTAPHOSPHATE

The crystal of cerium pentaphosphate with composition CeP₅O₁₄ belongs to monoc-linic system. The lattice parameters are as follows:α=8.797?, b=9.074?, c=13.124?, β=89°36′, Z=4. The space group is C_2h⁵-P₂₁/c. The diffraction data were collected using PW-1100 four-circle diffractometer. The number of independent diffraction data amounts to 2051. The structure is solved by heavy-atom method. Structure parameters were refined by full-matrix and block-diagonal least squares to a final R = 0.097. The result of structure analysis establishes that the structure is built up with discrete anionic ribbons linked by the cations in a complicated way. The polyhedral coordination of slightly distorted square antiprism is formed by eight oxygen atoms surrounding the Ce-cation. The shortest distance between two Ce ions is 5.967?.
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