1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Hexagional Bravais Latice Question

  1. Nov 6, 2009 #1

    TFM

    User Avatar

    1. The problem statement, all variables and given/known data

    The hexagonal close-packed structure (hcp) is the hexagonal Bravais lattice with a basis of two identical atoms associated with each lattice point, one at (0,0,0) and the second at

    [tex] r = \frac{2}{3}a_1 + \frac{1}{3}a_2 + \frac{1}{2} a_3 [/tex]

    where [tex]\left|a_1\right|[/tex] = [tex]\left|a_2 \right|[/tex] and [tex]a_1[/tex] and [tex]a_2[/tex] are at 120 degrees in the basal plane and [tex]a_3[/tex] is parallel to the c-axis. By considering the atoms to be hard spheres with nearest neighbour contact, show that the “c/a” ratio [tex]\frac{a_3}{a_1}[/tex] is 1.633.


    2. Relevant equations



    3. The attempt at a solution

    I am not quite sure what to do with this question. I am not quite sure how to get a3 and a1.

    Any ideas?

    many thanks,

    TFM
     
    Last edited: Nov 6, 2009
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted



Similar Discussions: Hexagional Bravais Latice Question
  1. Bravais Lattices? (Replies: 1)

  2. Bravais lattices (Replies: 0)

Loading...