University Chemistry ›› 2016, Vol. 31 ›› Issue (11): 76-80.doi: 10.3866/PKU.DXHX201603005

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Interpretation on Point Group of Dnd

Yan-Yan ZHU,Dong-Hui WEI,Wen-Jing ZHANG,Ming-Sheng TANG*()   

  • Published:2016-11-30
  • Contact: Ming-Sheng TANG
  • Supported by:


Point group in crystallography is one of the important subjects in structural chemistry.Some topics are very difficult to understand.To name a few, why does point group of D2d belong to tetragonal? Why are D4d and D6d not included in 32 kinds of crystallographic point groups? The two questions are easy to answer if we understand the following topic:for the Dnd point group, when n is odd, it contains an In symmetry axis; when n is even, it contains an I2n symmetry axis.In this work, graphic method and matrix method are adopted to clarify why the Dnd point group includes an S2n axis, and thus give explanations that D2d belongs to tetragonal as well as D4d and D6d are not included in 32 kinds of crystallographic point groups.

Key words: Point group, Dnd, Symmetry operation, Matrix


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