My Community

Hi,

I'm using 4.6 with the following KPOINTS file:
Automatic generation
0
Auto
50

When I run my optimization, I get this error:

VERY BAD NEWS! internal error in subroutine IBZKPT:
NKPT>NKDIM 10300

What is the best way to remedy this situation? Modify the KPOINTS? Increase NKDIM and recompile?

Thanks,
Dave

please note that the automatic k-mesh generation sheme will generate a
(LxMxN)/(#of symmetry operations of your lattice) k-mesh, with approximately
L=50*|b1| +0.5,
M=50*|b2| +0.5
N=50*|b3| +0.5
(b are the lengths of the recipocal lattice vectors, written eg in OUTCAR)
--> for a small unit cell (large b) with little symmetry (almost no symmetry operations) the generated k-mesh might ecxeed the upper limit of NKDIM (10000, at the moment), as has been in your case.
please check:
1) is such a large k-mesh necessary?
2) if yes, please increase the parameter NKDIM in main.F, please search for the the block following the line
-----hard limits for k-point generation package
and re-compile vasp.
Please note that you will have to change IKPTD and might have to change
NTETD (if you use Tetrahedron BZ integration) as well.