Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Atomic positions of iron

  1. Sep 3, 2013 #1
    how do i determine the different atomic positions of iron (bcc) as the number of atom increases.
     
  2. jcsd
  3. Sep 3, 2013 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    What do you mean with "number of atom increases"? In solid iron, the atoms are always in a lattice. The lattice structure can depend on pressure and temperature (and the presence of other atoms), you can look it up in phase diagrams.
     
  4. Sep 3, 2013 #3
    thanks for the reply, but my question has not been answered .am trying to use quantum espresso to determine surface energy of iron.to do this, i need to increase the number of slab or layers. i need to know how to increase the atomic position, when increasing the layers.Please,i need someone to help me out
     
  5. Sep 4, 2013 #4

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Please use the "New Reply" button to reply, do not open new threads for replies. I merged your two threads.

    So you are looking for coordinates of atoms in a bcc lattice? What is the orientation of the lattice in your coordinate system?
    Do you know the lattice constant?
     
  6. Sep 4, 2013 #5
    the lattice constant for iron is 2.863 angstrom. orientation of the lattice, 100,010,001,111,110,101,011
     
  7. Sep 4, 2013 #6

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    So you just have to add two layers (one for the "corners" one for the central atoms) each 2.863 angstrom?

    To me, it is still unclear where exactly your problem is.

    Which one?
     
  8. Sep 5, 2013 #7
    this is my input file. but my output is giving me error.overlap of 4 and 5

    &control
    calculation='scf'
    restart_mode='from_scratch',
    pseudo_dir = '/cygdrive/c/cygwin/espresso-4.2.1/pseudo/',
    outdir='/home/ABODE HARRY/tmp/',
    prefix='fe'
    /
    &system
    ibrav = 3, celldm(1) =5.217, nat= 5, ntyp= 1,
    ecutwfc = 40.0,ecutrho = 200.0,
    report=1,
    occupations='smearing', smearing='marzari-vanderbilt', degauss=0.05
    noncolin = .true.
    starting_magnetization(1) = 0.5
    angle1(1) = 45.0
    angle2(1) = 53.0
    constrained_magnetization='total'
    fixed_magnetization(1)=0.3,
    fixed_magnetization(2)=0.4,
    fixed_magnetization(3)=0.5,
    lambda = 0.5
    /
    &electrons
    conv_thr = 1.0e-9
    mixing_beta = 0.3
    /
    ATOMIC_SPECIES
    Fe 55.847 Fe.pz-nd-rrkjus.UPF
    ATOMIC_POSITIONS
    Fe 0.00 0.00 0.00
    Fe 0.50 0.00 0.00
    Fe 0.00 0.50 0.00
    Fe 0.50 0.50 0.00
    Fe 0.00 0.00 0.50
    K_POINTS AUTOMATIC
    4 4 4 1 1 1
     
  9. Sep 5, 2013 #8
    atomic position

    this is my input file. but my output is giving me error.overlap of 4 and 5.i don't know if my coordinates are wrong.pls, could you help on how to determine the correct atomic positions

    &control
    calculation='scf'
    restart_mode='from_scratch',
    pseudo_dir = '/cygdrive/c/cygwin/espresso-4.2.1/pseudo/',
    outdir='/home/ABODE HARRY/tmp/',
    prefix='fe'
    /
    &system
    ibrav = 3, celldm(1) =5.217, nat= 5, ntyp= 1,
    ecutwfc = 40.0,ecutrho = 200.0,
    report=1,
    occupations='smearing', smearing='marzari-vanderbilt', degauss=0.05
    noncolin = .true.
    starting_magnetization(1) = 0.5
    angle1(1) = 45.0
    angle2(1) = 53.0
    constrained_magnetization='total'
    fixed_magnetization(1)=0.3,
    fixed_magnetization(2)=0.4,
    fixed_magnetization(3)=0.5,
    lambda = 0.5
    /
    &electrons
    conv_thr = 1.0e-9
    mixing_beta = 0.3
    /
    ATOMIC_SPECIES
    Fe 55.847 Fe.pz-nd-rrkjus.UPF
    ATOMIC_POSITIONS
    Fe 0.00 0.00 0.00
    Fe 0.50 0.00 0.00
    Fe 0.00 0.50 0.00
    Fe 0.50 0.50 0.00
    Fe 0.00 0.00 0.50
    K_POINTS AUTOMATIC
    4 4 4 1 1 1
     
  10. Sep 5, 2013 #9

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    I have no idea how that config file works, so I don't see how I could help there.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Atomic positions of iron
Loading...