[Wien] symmetry and *in2

[Peter Blaha]

a) Is this within GGA or LDA. Make the same test in LDA (GGA requires
gradients and they are calculated on different meshes in the different
unit cells. However: I would say the difference in energies is too large
for this explanation.

b) k-mesh: It is clear that your 2 k-meshes cannot be made "equivalent".
So in principle you must converge E-tot with respect to k-mesh for both
structures. How does the E change, when you use a much denser mesh (2-4x)?

Are you using TETRA or some smearing ? (the latter schould be prefarable
for such structures)

> I calculated 5 layers of Pd(113) surface.
>
> At first, I constructed a cuboid structure
> (113_90.struct). (it contains 10 Pd atoms). Using
> different k-mesh, :DIS of each case was coverged very
> well. For example, when k-mesh is 9*3*1 (irreducible
> kpoint is 10), the total energy is -100940.549689 Ry.
>
> Then, we reduced half of the cuboid volum to get unit
> structure (113_106.struct). (it contains only 5 atoms
> and angle gamme is not 90 degree but 106 degree).
> Also, different k-mesh are used to calculate and each
> one was convergence. When k-mesh is 5*9*1 (irreducible
> kpoints is 15), the total energy is -50470.403835 Ry.
>
> For the two slab structures, the thickness of vacuum
> is enough. So if we divided the first total energy by
> 2, the value must be very near to the second total
> energy.
> Unfortunately, -100940.549689/2=-50470.2748445 Ry, it
> is very different from the second total energy
> -50470.403835 Ry. There are the same mistakes of
> others different k-meshes.
>
> I don't know it is my fault or the bug of programme.
> (My wien2k code was download on 29, Jan. 2004)
>
> by the way, the two R*Kmaxs are the same.
> I only attach two structure files. (Becase other files
> too large). If you want other files, I will send you


                                      P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
--------------------------------------------------------------------------