[QE-users] Adding zero weight k-point in hybrid functional calculation

[Ye Luo]

Hi all,

When I used hybrid functional, there were some results I couldn't
understand.
When I added 8 extra k-points with weight 0, the total energy doesn't
change. This is good.
However, the eigenvalues for the zero weight k-points are very different
from the ones having weights, almost by 10 eV. Could somebody explain me
why they are so different?

I'm using 6.2.1 and the input/output files are attached.

Best,
Ye

K-points with non zero weights

          k = 0.0625 0.0625 0.0970 ( 36979 PWs)   bands (ev):

*   -53.0839 -52.9906 -28.0827 -28.0368 -27.9204* -27.8593 -27.8356 -27.7968
   -12.1235 -10.9444 -10.2473 -10.1599   1.3972   1.8189   2.3804   3.1172
     3.1651   4.5989   4.6761   5.0642   6.2827   6.6244   6.7135   7.1938
    12.2533

          k = 0.0625 0.0625 0.2911 ( 36988 PWs)   bands (ev):

   *-53.1117 -53.0153 -28.0928 -28.0546 -28.0480* -27.9769 -27.9020 -27.8822
   -11.7609 -10.6965 -10.3172 -10.2280   1.8505   2.1602   2.7827   3.1244
     3.2151   4.2624   5.0855   5.1805   5.3720   6.2135   6.2331   7.1360
    12.4254
....

K-points with zero weights

          k =-0.2500 0.5000-0.1941 ( 37004 PWs)   bands (ev):

*   -42.5037 -42.4122 -19.3809 -19.3714 -19.2420 *-19.2141 -19.1805 -19.1305
    -3.4162  -3.3687  -2.3823  -2.3308   7.9738   8.0176   8.9348   8.9699
    10.2413  10.2707  11.3846  11.4094  11.5913  11.6235  12.5038  12.5195
    15.5560

          k =-0.2500 0.5000 0.5823 ( 36986 PWs)   bands (ev):

 *  -42.4692 -42.3774 -19.5967 -19.5241 -19.2954* -19.2666 -19.1922 -19.1602
    -2.9201  -2.8660  -2.4351  -2.3823   7.9845   8.0040   8.8546   8.8783
     9.9004   9.9266  11.0131  11.0685  11.6606  11.6923  12.7962  12.8092
    15.2910

===================
Ye Luo, Ph.D.
Leadership Computing Facility
Argonne National Laboratory
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