Band Indices mixed

[Edward Kong]

Dear Developers,

I tried to calculate a GW band structure with Epsilon and Sigma codes. The Inteqp codes are used to give the interpolated some band structures but it seems that the indices of different bands are mixed. I presume that it might be led by the failure of finite difference when finding the QP correction, or we just can mix the band indices here? Thanks for your help in advance.

Best,

Mingran

[Edward Kong]

The band structure is attached.

[Zhenglu Li]

Dear Edward,

It is possible and often that the GW corrections will reorder bands.  The bands will still be labeled by their DFT indices, but the energies may be swapped in this case.

Best,

Zhenglu

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From: Edward Kong <kmr754...@gmail.com>
Sent: Friday, June 28, 2024 2:11 AM
To: BerkeleyGW Help <he...@berkeleygw.org>
Cc: Edward Kong <kmr754...@gmail.com>
Subject: Re: Band Indices mixed

 

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[Edward Kong]

Dear Zhenglu,

Great! Thanks for your kind reply!

Best,

Mingran

[tieshuan dong]

Dear Zhenglu,

I seem to have encountered the same problem as Edward Kong. When calculating the GW band, there is some mixing of band indices in the bandstructure.dat file output by Inteqp. The GW band obtained through plot_bandstructure.py script processing is very strange. The band gap of the system I calculated is only about 0.1eV, and I don't know how to solve this problem.

[Zhenglu Li]

Hi Tieshuan,

Looking at the LDA bands, the system appears as a metal.  Inteqp does not resolve metals.  One way to overcome this is to use Wannier interpolation.  There is sig2wan.x utility in BGW and it generates .eig file for Wannier90 to interpolate.

Best,

Zhenglu

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From: tieshuan dong <tieshu...@gmail.com>
Sent: Monday, April 7, 2025 7:13 PM
To: BerkeleyGW Help <he...@berkeleygw.org>
Cc: Zhenglu Li <zhen...@usc.edu>

Subject: Re: Band Indices mixed

 

Dear Zhenglu, I seem to have encountered the same problem as Edward Kong. When calculating the GW band, there is some mixing of band indices in the bandstructure. dat file output by Inteqp. The GW band obtained through plot_bandstructure. py script

To view this discussion visit https://groups.google.com/a/berkeleygw.org/d/msgid/help/53fdac60-92e4-4e66-801d-42bc66d14c42n%40berkeleygw.org.