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A problem from crystallography

  1. Aug 24, 2011 #1
    1. The problem statement, all variables and given/known data

    In a tetragonal lattice a=b=0.25 nm and c= 0.18nm, deduce the spacing between (1,1,1) planes.

    2. Relevant equations

    the basic equation in this case is

    3. The attempt at a solution

    here in the question we are provided with the h,k,l value. my doubt is how to find lattice constant a. for a tetragonal crystal we are having diffrent values for c and a,b. so the lattice constant will not be the same through out the crystal, rite? how to solve this?
    Last edited: Aug 24, 2011
  2. jcsd
  3. Sep 2, 2011 #2
    [tex]d = \frac{2\pi}{\left|\vec{G}\right|}[/tex]
    Where [itex]\vec{G}[/itex] is just the shortest reciprocal lattice vector orthogonal to that plane.

    I suggest first finding the three reciprocal primitive vectors. And then construct the shortest reciprocal lattice vector orthogonal to the (1,1,1) planes from those.
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