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lanlee木虫 (小有名气)
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[交流]
求助关于点群的对称性
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我做的是关于 La2CaB10O19，这个化合物是单斜晶系，C2空间群，La是十配位的，钙是八配位， La2CaB10O19 is a biaxial single crystal which belongs to the monoclinic system with space group C2 with two formula units per cell.2 The lattice parameters of LCB crystal are a=11.043 Å, b=6.563 Å, c=9.129 Å, α =β =90°, and γ=91.47°. The LCB crystal is a member of the newly synthesized NLO borate crystals RCB （R2CaB10O19） family, where R represents rare-earth elements.10 LCB is absolutely insensitive to moisture, and has a hardness of 6.5 Mohs, allowing easy cutting and optical polishing.2 The crystal structure contains B5O12 double-ring pentaborate groups, which are linked together forming infinite two-dimensional double layer. The layer is situated almost perpendicularly to the c axis of the crystal. The La atoms are located in layers, while Ca atoms are located between two layers 我想请教的是La位置具有什么对称性，还有Ca具有什么对称性，要知道这个的话，需要什么数据！ 谢谢！ [ Last edited by lanlee on 2007-9-26 at 17:32 ] |
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