[Pw_forum] translation of lattice planes

[vicky singh]

Hi Linh
thanks a lot for your suggestion. but u didn't get my problem. I think i was
too brief. actually i have made a supercell with 1x1x6 for Ni  100 plane i.e
12 layers as
CELL_PARAMETERS {cubic}
6.66    0       0
0       6.66    0
0       0       39.96

ATOMIC_POSITIONS {crystal}
Ni      0.000   0.000   0.000
Ni      0.5     0.5     0.0
Ni      0.5     0.0     0.0833
Ni      0.0     0.5     0.0833
Ni      0.000   0.000   0.1667
Ni      0.5     0.5     0.1667
Ni      0.5     0.0     0.2500
Ni      0.0     0.5     0.2500
....
out of the 12 layers i want to rigidly translate 6 layers in any x or y
direction. when i change the coordinates of atoms in x or y the supercell
gets deformed. how to do that.

vicky


On Sat, Feb 13, 2010 at 3:48 PM, Ngoc Linh Nguyen <nnlinh at sissa.it> wrote:

>
> > hi
> >
> > I am studying nickel. can anybody help me how to translate few planes in
> a
> > supercell
>
> In order to estimate the positions of atoms on the planes in the
> supercell, you should clarify:
>    - which kind of structure that you want to consider, i.e. (111) or
> (100) or (110) surfaces.
>    - size of supercell, such as: 2x2x2, or 2x2x4. The height of vacuum
> space.
>    - Then, you handle the positions of the atoms associate with the sizes
> of the supercell.
>
> I would like to send to you an example to make clear about forming a
> supercell.
>
> > and how i can constrain few atomic plane in my code. when i am
> > changing the x, y, z coordinate to move a bit the complete structure
> > itself is changing.
>
> In order to constrain the atoms on the planes, in the card
> ATOMIC_POSITION, you put as:
> Ni    X(1)  Y(1) Z(1)   0 0 0
> it means that the positions of that atom will be fixed while relaxing of
> models is happening.
>
>
> Linh
> >
> > vicky
> >
> > research student
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
>
>
> -----------------------------------------------------
>  Nguyen Ngoc Linh, PhD Student
>  c/o:   SISSA & CNR-INFM Democritos,
>        via Beirut 2-4, 34014 Trieste (Italy)
>  email: nnlinh at sissa.it
>  phone: +39 04 03787 319
>  skype: ngoclinh84phys
> -----------------------------------------------------
>
>
>
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