Problem in understanding GW+BSE corrected optical response

Deals with issues related to computation of optical spectra, in RPA (-o c) or by solving the Bethe-Salpeter equation (-o b). Includes local field effects, excitons, etc.

Moderators: Davide Sangalli, Daniele Varsano, andrea.ferretti, andrea marini, Conor Hogan, myrta gruning

haseebphysics1
Posts: 145
Joined: Sat Aug 17, 2019 2:48 pm

Re: Problem in understanding GW+BSE corrected optical response

Post by haseebphysics1 » Tue Jul 14, 2020 2:39 pm

Dear Daniele, thanks for the quick response!

Yes, there are 72 k-points but there are 360 occupied states,

Code: Select all

[X]States summary         : Full        Metallic    Empty
                                 0001-0320               0321-0740
and I included the BSEBands as follows.

% BSEBands
290 | 440 | # [BSK] Bands range
%

So, should not be there 71 VB and 80 CBs. And hence dimension should be 72 x 71 x 80 ??

Regards,
Haseeb Ahmad
MS - Physics,
LUMS - Pakistan

User avatar
Daniele Varsano
Posts: 2605
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: Problem in understanding GW+BSE corrected optical response

Post by Daniele Varsano » Tue Jul 14, 2020 2:47 pm

From what you posted I can see 320 occupied states.

Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

haseebphysics1
Posts: 145
Joined: Sat Aug 17, 2019 2:48 pm

Re: Problem in understanding GW+BSE corrected optical response

Post by haseebphysics1 » Tue Jul 14, 2020 3:00 pm

Dear Daniele,
An you are including 31 valence and 120 conduction bands.

So, how you got these numbers from? I have not provided these settings in the input!

Regards,
Haseeb Ahmad
MS - Physics,
LUMS - Pakistan

User avatar
Daniele Varsano
Posts: 2605
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: Problem in understanding GW+BSE corrected optical response

Post by Daniele Varsano » Tue Jul 14, 2020 3:55 pm

You provided in the input:

Code: Select all

% BSEBands
 |   290 |  440 |                 # [BSK] Bands range
 %
which means to include valence bands from 290 to 320 (31 valence bands) and conduction bands from 321 to 440 (120 conduction bands).

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

haseebphysics1
Posts: 145
Joined: Sat Aug 17, 2019 2:48 pm

Re: Problem in understanding GW+BSE corrected optical response

Post by haseebphysics1 » Tue Jul 14, 2020 4:01 pm

Oh, sorry, that question was not worth posting! I was mixing it with another system where it was 360 VBs! In my mind, I was stucked at 360 and calculating w.r.t to 360 filled states!

Sorry about this!


Thanks,
Haseeb Ahmad
MS - Physics,
LUMS - Pakistan

Post Reply