Crystallography question

Discussion in 'Physics' started by boks, Mar 11, 2009.

  1. boks

    Thread Starter Active Member

    Oct 10, 2008
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    According to my handbook, rutile (TiO_2) has a primitive tetragonal cell consisting of 6 atoms. How is that possible when each lattice point contains 1/8 atom or molecule?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. studiot

    AAC Fanatic!

    Nov 9, 2007
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    The rutile structure is not close packed. It shows 6:3 coordination which means that each titanium atom is surrounded by 6 (not 8) oxygen atoms arranged at the vertices of an octahedron.

    An octahedon has 8 faces but only 6 vertices


    Each oxygen is coordinated to 3 titaniums in a planar equilateral triangle.
     
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