1. Not finding help here? Sign up for a free 30min 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!

We have that for a crystal the lattice parameters

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

    We have that for a crystal the lattice parameters (in angstrom and degree) are:

    a b c (in Angstrom)
    10.5 10.5 10.5

    [itex]\alpha[/itex] β γ (in degree)
    109.5 109.5 109.5


    Find the lattice vectors components.


    2. Relevant equations


    3. The attempt at a solution

    The way I solved the problem:

    a_1 (first component of the vector a) = 0
    a_2 = sin (109.5) * 10.5 = 9.8977356555
    a_3 = cos (109.5) * 10.5 = -3.5049720195

    b_1 = sin (109.5) * 10.5 = 9.8977356555
    b_2 = 0
    b_3 = cos (109.5) * 10.5 = -3.5049720195

    c_1 = sin (109.5) * 10.5 = 9.8977356555
    c_2 = cos (109.5) * 10.5 = -3.5049720195
    c_3 = 0


    The matrix with the vectors' components is then:

    0.0000000000 9.8977356555 -3.5049720195
    9.8977356555 0.0000000000 -3.5049720195
    9.8977356555 -3.5049720195 0.0000000000


    Is this correct ?

    One could also write this matrix as:

    0.0000000000 -3.5049720195 9.8977356555
    9.8977356555 0.0000000000 -3.5049720195
    9.8977356555 -3.5049720195 0.0000000000

    (notice the interchange in the the first vector components). Which matrix is correct ? The ordering will be definitelly important for the atom positions.

    Thank you very much for any help.
    Eduard
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 5, 2011 #2

    ehild

    User Avatar
    Homework Helper
    Gold Member

    Re: Vectors

    Check if those vectors really enclose 109.5° angle.

    ehild
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: We have that for a crystal the lattice parameters
  1. Lattice points (Replies: 2)

  2. Eliminating Parameters (Replies: 1)

Loading...