How to create a slab?

Message

uceetam · #1 Post by **uceetam** » Mon Jun 11, 2012 6:39 pm

Can anybody help me with this task? I am trying to create slab of Silicon with

POSCAR

Si
1
5.430 0.000 0.000
0.000 5.430 0.000
0.000 0.000 5.430
8

Direct
0.000 0.000 0.000 T T T
0.500 0.500 0.000 T T T
0.000 0.500 0.500 T T T
0.500 0.000 0.500 T T T
0.250 0.250 0.250 T T T
0.750 0.750 0.250 T T T
0.750 0.250 0.750 T T T
0.250 0.750 0.750 T T T

So basically I have to create a computational cell consisted of three unit cells on on top of the other so as to remove layers of Silicon from both sides and get a slab of silicon.

I am basically stuck on what should I do to get a computational cell consisted of three layers of the unit cell. Since the unit cell of Silicon consists of 8 atoms does it mean that in the POSCAR file the total atoms should be 3*8=24 and then find the direct coordinates of each silicon atom?

Thanks

var · #2 Post by **var** » Thu Jun 21, 2012 3:19 am

Hi uceetam,

for me some initial steps are:
1) you should know the surface (111, 110, 531, etc, Miller)
2) surface periodicity: 1X1, 2X1, 2X2, etc and the lattice vectors of the supercell
3) the supercell will be made of the slab and the vacuum region in the direction of the normal to the surface

Hope these initial steps help you.
Cheers,

uceetam · #3 Post by **uceetam** » Fri Jul 06, 2012 3:08 am

Thank you..

jber · #4 Post by **jber** » Wed Aug 01, 2012 2:33 pm

Please consider ASE: https://wiki.fysik.dtu.dk/ase/ase/surfa ... ce-section