WFN ifmin/ifmax fields are inconsistent

Submitted by Fabiof on Thu, 05/18/2017 - 06:04

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When doing the absorption calculation to get the BSE done on 2D h-BN, i have the following error:

WFN ifmin/ifmax fields are inconsistent:
- there is a valence state above the middle energy
- there is a conduction state below the middle energy
Possible causes are:
(1) Your k-point sampling is too coarse and cannot resolve the Fermi energy.
Try to carefully inspect your mean-field energies, and consider using a finer
k-grid.
(2) You are using eqp.dat and the QP corrections change the character of some s
tates
from valence<->conduction. In this case, you should use another mean-field the
ory
that gives the same ground state as your GW calculation.
(3) You are running inteqp, but you are either shifting the Fermi energy or usi
ng
restricted transformation.

ERROR: WFN ifmin/ifmax fields are inconsistent

My question is if i have to have a finer grid for WFN_co or WFN_fi and WFNq_fi.

I have tested on the WFN_fi and WFNq_fi and it is not working.

Thanks,

Fabio

Submitted by babarker on Mon, 05/22/2017 - 12:18

Hello Fabio,

The information about the "ifmin" and "ifmax" is accessible by running

wfn_rho_vxc_info.x

on the wavefunction files of interest. (Pipe the output to text files.) From there, you can see which bands are occupied at the various k-points, in each wavefunction.

From experience, this error message can come up when dealing with metallic systems, though 2D Boron Nitride should have a fairly large gap. Do you in fact have an insulating system?

Best,
Brad

Submitted by Fabiof on Tue, 05/23/2017 - 06:37

The error was in the pseudopotentials. The pseudopotential of the N atom had the information of the B atom.

I did some mistake when copying the files to do the absorption calculation. Instead of having 4 valence bands, the scf calculation only reported 3.

Thanks for your help,
Fabio

Submitted by babarker on Tue, 05/23/2017 - 14:27

Hello Fabio,

Fantastic! Best wishes for future calculations.

Best,
Brad