[Wannier] spread

[Vivek Ranjan]

Hello,

I am trying to calculate wannier function of BN sheet. The way the unit
cell is constructed, I have chosen (12,1,1) kpoint mesh for scf
calculation. Then I do an nscf calculation with 4 kpoints (4,1,1). The
spread of one of wannier function is 26 A. I run several steps (more than
20000) and still it does not converge. The question is how to reduce this
spread ?

I tried putting more kpoints by doing (12,2,2) scf calculations and 16
kpoints (4,2,2) for nscf and wannier parts. The problem is instead of 16
kpoints in the nscf that I hand put in the file, pwscf always generates 24
kpoints. The additional kpoints are shifted kpoints that I put. It never
happened to me before and wondering why it is happening ?

(12,1,1) scf, and (4,1,1) kpoints has no such problems.

Thanks,

Vivek,
Physics, NCSU.