Qbox List

Hi Francois,

I am going to run a few calculations with k-points on the WO3 surface. I am wondering if there is any specific kind of parallelism implemented in Qbox that I can exploit for calculations with k-points (something similar to pools in Quantum-ESPRESSO).

Thank you

Best,
Matteo

Hi Matteo,
Currently there is no parallelism on k-points, since the focus is mostly on large-cell gamma point MD simulations. If you use k-points, make sure to specify all equivalent k-points (except for k, -k symmetry which is included in all algorithms by default). So for a slab calculations, you could use:

kpoint delete 0 0 0
kpoint add 0.25 -0.25 0.00 0.500000
kpoint add 0.25 0.25 0.00 0.500000

The first "kpoint delete" command is used to remove the (default) k=0 point.
The two k-points added then give you the equivalent of a 2x2x1 grid.

Note that this should only done in the first calculation when defining the system. The restart files then contain all the k-point information and the load command reads it accordingly.

You can use the program kpgen (in util/kpgen/kpgen.C) to generate other grids.

Francois