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Homework Help: Finding shortest distance in bcc

  1. Feb 19, 2009 #1
    1. The problem statement, all variables and given/known data

    Barium crystallizes in a body centered cubic structure in which the cell edge length is 0.5025 nm. Calculate the shortest distance between neighboring atoms in the crystal.

    2. Relevant equations

    Avagodro's number

    3. The attempt at a solution

    0.5025 x 10^-7 cm ( 1/2atoms) (6.022 x 10^23 atoms)

    That's as much as I know so far, I can't use bragg's law because I don't have the angle nor the order nor the wavelength to figure it out. How should I solve this?
  2. jcsd
  3. Feb 19, 2009 #2


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    Hi vipertongn! :smile:

    I dunno what body centered cubic structure or cell edge length is,

    but this looks like a simple geometry problem to me …

    they've given you the geometrical pattern and one length, and you have to calculate another length. :wink:
  4. Feb 20, 2009 #3
    http://cst-www.nrl.navy.mil/lattice/struk.picts/a2.s.png [Broken]

    See if you can visualize the triangle...You know the triangle sides. Now calculate the bond lengths from ratios of the triangles.
    Last edited by a moderator: May 4, 2017
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