K-Point Convergence for Surface Slab.

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Sharani
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K-Point Convergence for Surface Slab.

#1 Post by Sharani » Fri May 21, 2010 4:02 pm

I am trying to build a Ag(110) surface slab in order to study the adsorption of an oxygen molecule adsorbed on a Ag(110) surface. Regarding k-point convergence, the VASP manual on Page 132 states, "if you want to calculate surface energies within 10 meV you should probably increase the k-mesh till your energy is converged to 1 meV". My question is, if I check for k-point convergence by comparing the energy difference between two different k-point meshes for the same slab, should I consider the total energy difference or the energy difference divided by the number of atoms in the surface slab. Referring to the earlier statement from the manual, should the energy or the energy/atom be converged to 1 meV?

I would be very grateful for some help in this matter.

Regards,
Sharani
Last edited by Sharani on Fri May 21, 2010 4:02 pm, edited 1 time in total.

alex
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K-Point Convergence for Surface Slab.

#2 Post by alex » Sat May 22, 2010 9:42 am

The quantity you are interested in should be much larger (e.g. like the factor of 10) than the error introduced by approximations. That's the point.

Cheers,

alex
Last edited by alex on Sat May 22, 2010 9:42 am, edited 1 time in total.

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