[Pw_forum] vectors for post processing calculation for hexagonal structure

[Gabriele Sclauzero]

Hello,

Il giorno 25/feb/2011, alle ore 17.58, pari shok ha scritto:

> Hello,
> I was wondering how I could possibly get the STM (or other post processing calculations) on the surface of a hexagonal structure.
> If I define the vectors as:
> e1(1):1 e1(2):0 and e1(3):0 
> e2(1):0 e2(2):1 and e2(3):0
> and the origin as:
> x0(1):0 x0(2):0 x0(3):the slab length (say 20 Angstroms),
> will it cover the entire surface of the hexagonal structure?

I don't think so. The documentation says:

      !!! x0, e1, e2 are in alat units !!!

which usually means that these vectors are in a cartesian frame of reference and in units of celldm(1).

Moreover, it also says

      Variables:      e1(i), e2(i), i=1,3
      
      Type:           REAL
      Description:    3D vectors which determine the plotting plane
                      (must be orthogonal)

while the vectors which define the basal plane of the hexagonal lattice are obviously not orthogonal.

If you need to visualize the charge in planes which are normal to one of the crystal axes you can use iflag=3 and output_format=5.
Then open the file with xcrysden, visualize the grid data (menu on the top right) and select the plane you want. Finally you can make nice eps, jpeg, png, ... figures.

> I appreciate your help.

You're welcome. However we appreciate that you sign with your affiliation too. Thanks!


HTH

GS

> P Shok
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§ Gabriele Sclauzero, EPFL SB ITP CSEA
   PH H2 462, Station 3, CH-1015 Lausanne

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