ABINIT Discussion Forums

Hello dear abiniters! Sorry for my poor english.
From tutorial (abinit/doc_6.0.2/input_variables/varbas.html#shiftk) when we use FCC lattice, the best way to sample k-space is to use nshiftk 4 and shiftk 0.5 0.5 0.5
0.5 0.0 0.0
0.0 0.5 0.0
0.0 0.0 0.5
Then, if we write this values in our example.in file and run our calculation, after the end of calculation in example.out file we don't find nshiftk, and shiftk will be only = 0.5 0.5 0.5.
My question is: Why it is happened?
As an example you can compare ~abinit/tests/tutorespfn/Input/tnlo_2.in and ~abinit/tests/tutorespfn/Refs/tnlo_2.out

Hello,

The idea is that this combination of 4 shiftk's with ngkpt n n n for FCC lattice corresponds to a k-point mesh defined by kptrlatt -n n n n -n n n n -n (if I remember well) and only one shift of the mesh. That might be the output of your simulation.

David

You probably did not specify nshiftk 4. The default is 1 (that's why it is not written to output), and only the first line of your shiftk is being read.

Matthieu