ABINIT Discussion Forums

i give a error message when use to kptopt negative value in screening calculation

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m_bz_mesh.F90:399:BUG
Not allowed value for kptopt: -4
Action : contact ABINIT group.
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Dear cengiz,

I notice you had a lot of trouble setting the kpoint grid for a GW calculation.
The solution to your problem is simple. You must:

1) Make a ground state calculation to produce a KSS file,
with a kpt grid defined appropriately with kptopt, ngkpt or kptrlatt.
For a GW calculation, you must set kptopt to a positive value.

2) Use exactly the same kpt grid for the screening calculation.

3) Use exactly the same kpt for the sigma calculation,
Then, the variable kptgw lets you choose a set k-points which must belong to the kpt grid you used,
in the KSS file.


This is quite basic, so please make sure you complete and fully understand the GW tutorial, and that you read the description of the aforementioned variables. Also, I would like to insist that before you ask questions on the forum, you search for similar posts, and that you keep posts related to the same problem in a single topic. If you help yourself, the forum community will be pleased to help you.

thank you

Dear Gabriel

i want to calculate wurtzide ZnO band structure . i calculated ZnO band structure and it is band gap is wrong
after i try to calculate true band gap with GW
it calculate band gap but k-point that was corrected is 0.125 0.125 0.125
is this GAMA point ?
i know gama point for hexagon crystal is 0.0 0.0 0.0

for example

GW correction step

1 calculate kss file
this point . i change k point mesh with ngkpt and shiftk and kptopt
2 calculate screening
here , when i used to kptopt and ngkpt shiftk , give error mesage
we let to calculate usual k-mesh that is calculated by abinit default . this mesh does not contain usual k point for hexagon brillouin zone

if i change k point in kss file and let to calculate default k-mesh in screening calculation step , give error message

how to fix k-mesh ? i want to
is this impossible ?

thank you for your interesting

hi everyone,
I am new user of Abinit.
I want to draw bandgap. how i can do that?
thanks in advance