[ase-users] Making orthorgonal 3x3x6 of Pt(111)

[Eric Hermes]

Kofi,

An orthogonal unit cell of an FCC(111) surface must have an even number
of atoms in the Y direction due to the symmetry of the surface.

Here's a simplified ACII drawing of a 3x4 orthogonal FCC(111) surface:

o o o
 o o o
o o o
 o o o

If you repeat that vertically and horizontally, it makes a perfect
FCC(111) surface (exercise left to the reader).

Now, what you want is this:

o o o
 o o o
o o o

But if you repeat that vertically, you get this:

o o o
 o o o
o o o
o o o
 o o o
o o o

Which is not an FCC(111) surface. That's why the Y direction must be
even.

Eric

On Fri, 2018-01-12 at 00:21 +0000, Kofi Oware Sarfo via ase-users
wrote:
> Hi,
> I would like to ask for some assistance with regards to  the making
> of a 3 x3x6 (x,y,z) orthogonal supercell of Pt(111) . I tried to
> make  it using the python script below but that yeilds an error that
> the y value must be an even number. Is there any other way possible 
> that I could make  this model in its orthogonal form?
> 
> from ase import *
> from ase.lattice.surface import *
> from ase.visualize import view
> from ase.io import write
> 
> 
> #create Pt(???) unit cell
> slab = fcc111('Pt',size=(3,3,6),a=3.98,vacuum=0,orthogonal=True)  #
> for PAW.52_PBE
> 
> view(slab)
> #write('Pts.POSCAR',slab)
> 
> 
> regards
> Kofi Sarfo Oware
> 
> _______________________________________________
> ase-users mailing list
> ase-users at listserv.fysik.dtu.dk
> https://listserv.fysik.dtu.dk/mailman/listinfo/ase-users