Gamma centered k-point grids

[hh]

I tried to find a suitable kpoints mesh for 111 surface, and took a look at http://cms.mpi.univie.ac.at/vasp/vasp/node278.html

Question: Which k-points should I use

and I saw :

Gamma centered 3x3
Automatically generated mesh
3
Reciprocal lattice
0.00000000000000 0.00000000000000 0.00000000000000 1
0.33333333333333 0.00000000000000 0.00000000000000 6
0.33333333333333 0.33333333333333 0.00000000000000 2

Gamma centered 4x4
Automatically generated mesh
4
Reciprocal lattice
0.00000000000000 0.00000000000000 0.00000000000000 1
0.25000000000000 0.00000000000000 0.00000000000000 6
0.50000000000000 0.00000000000000 0.00000000000000 3
0.25000000000000 0.25000000000000 0.00000000000000 6

and so on,

but I wondered since,
0.33333333333333 0.00000000000000 0.00000000000000 6
and
0.33333333333333 0.33333333333333 0.00000000000000 2
are equal

and for 4x4


0.25000000000000 0.00000000000000 0.00000000000000 6

and

0.25000000000000 0.25000000000000 0.00000000000000 6

are equal in the IBZ and also for the other points in 5x5, 6x6.

maybe you have used another basis vectors for the BZ of the
the hexagonal cells.

Thank you very much for your help.

H.Hashemi

[admin]

I would suggest to use an odd Monkhurst-Pack k-mesh, nxnx1.

[Lecuyern]

May I ask why you suggest this one?

[danielk]

See Monkhorst & Pack, Phys. Rev. B, 13, 5188 (1976). MP provides the most efficient distribution of k-points.