[QE-users] calculated number of k_points calculated different than instructed in the nscf input file

[Paolo Giannozzi]

A 'nscf' calculation assumes that the k-point grid covers the 
Irreducible Brillouin Zone computed with the crystal symmetry. If your 
grid covers the IBZ computed for a higher symmetry, the missing k-points 
will be added. Use calculation='bands' or disable the symmetry check on 
k-points if you want to stick to the k-point grid you provided

Paolo

On 17/04/2024 06:13, wenusaras wrote:

> After a scf calculation, I performed a nscf calculation using a 10 10 1
> grid.
> 
> K_POINTS {crystal}
> 100
>    0.00000000  0.00000000  0.00000000  1.000000e-02
>    0.00000000  0.10000000  0.00000000  1.000000e-02
>    0.00000000  0.20000000  0.00000000  1.000000e-02
> ...
>    0.90000000  0.90000000  0.00000000  1.000000e-02
> 
> Though the nscf input file is instructed to do so, the nscf.out files
> calculates for 247 kpoints.
> 
>       number of k points=   247  Marzari-Vanderbilt smearing, width (Ry)=
>   0.0150
>                         cart. coord. in units 2pi/alat
>          k(    1) = (   0.0000000   0.0000000   0.0000000), wk =
> 0.0200000
>          k(    2) = (   0.0000000   0.1154701   0.0000000), wk =
> 0.0066667
>          k(    3) = (   0.0000000   0.2309401   0.0000000), wk =
> 0.0066667
> ...
>          k(  247) = (   1.8000000  -0.9000000   0.0000000), wk =
> 0.0066667
> 
> 
> Could you please let me know why this happens and how could I calculates
> for 100 kpoints as instructed in nscf.in?
> 
> 
> -- 
> Thank You
> Wenusara Satheekshana
> 
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-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine Italy, +39-0432-558216