New Coulomb cutoff in version 5.1

Concerns issues with computing quasiparticle corrections to the DFT eigenvalues - i.e., the self-energy within the GW approximation (-g n), or considering the Hartree-Fock exchange only (-x)

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

Post Reply
sdwang
Posts: 287
Joined: Fri Apr 09, 2010 12:30 pm

New Coulomb cutoff in version 5.1

Post by sdwang » Wed May 25, 2022 6:36 am

Dear developers,
I noticed a new cutoff strategy has been implemented in the new version 5.1. As for the "slab z" cutoff of 2D system, how to set the cutoff size along the z direction? Could we just set it as the size of "box xy"? And another question is if we want to take the benefit of the rimW integration, as described in the paper "arXiv:2205.11946v1", to do GW calculation, which parameter we should activate? Does this rimW technique accelerate BSE calculations w.r.t the k-point also?
Thanks!
Best

Shudong
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

User avatar
Daniele Varsano
Posts: 3773
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: New Coulomb cutoff in version 5.1

Post by Daniele Varsano » Wed May 25, 2022 8:46 am

Dear Shudong,
how to set the cutoff size along the z direction?
There is no need to set any zcut, it is automatically set by the code.

About the rimW a tutorial will be published soon. Please find attached an input example.
The parameter to set to activate it are:

Code: Select all

RIM_W. #  as runlevel
RandQpts=3000000                  # [RIM] Number of random q-points in the BZ
RandGvec= 97                RL    # [RIM] Coulomb interaction RS components
RandGvecW = 15              RL
CUTGeo= "slab z"  
The meaning of each variable should be clear from the paper you mention.

Code: Select all

Does this rimW technique accelerate BSE calculations w.r.t the k-point also?
You can try, but it is discouraged, still some systematic testing is needed.

Best,
Daniele
You do not have the required permissions to view the files attached to this post.
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/

sdwang
Posts: 287
Joined: Fri Apr 09, 2010 12:30 pm

Re: New Coulomb cutoff in version 5.1

Post by sdwang » Wed May 25, 2022 9:12 am

Dear Daniele,
Thank you for the quick reply. I will try it.
Best

Shudong
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

Sumit
Posts: 20
Joined: Wed Jun 09, 2021 12:10 pm

Re: New Coulomb cutoff in version 5.1

Post by Sumit » Mon May 30, 2022 3:17 pm

Dear Developer,

Is no box sides are needed for this slab z method as found in your shared input_RIMW.in file?
CUTGeo= "slab z"
% CUTBox
0.000000 | 0.000000 | 0.000000 | # [CUT] [au] Box sides
%

Thank You

Regards
Sumit Kukreti
Ph.D. Scholar
IIT Jodhpur INDIA

User avatar
Daniele Varsano
Posts: 3773
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: New Coulomb cutoff in version 5.1

Post by Daniele Varsano » Tue May 31, 2022 7:47 am

Dear Sumit,

no, the slab cutoff does not require any box size, as the cut is done on the Wigner-Seitz cell as explained here:
https://arxiv.org/pdf/2205.11946.pdf

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/

sdwang
Posts: 287
Joined: Fri Apr 09, 2010 12:30 pm

Re: New Coulomb cutoff in version 5.1

Post by sdwang » Wed Jun 29, 2022 2:40 am

Dear all,
I am trying the newly published Coulomb cutoff and it stopped with anything complaint in the log and the report(It seems the problem is with RIM integrals). My system is a 2D hBN.
Attached are the input, log, and report files.
Thanks!

Best


Shudong

PS: When I finished the chi calculation with RIM_W and then remove it, the sigma part goes smoothly and I got the final GW results. But this would miss something about rim integral.
You do not have the required permissions to view the files attached to this post.
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

Alberto Guandalini
Posts: 8
Joined: Thu Jun 24, 2021 9:10 am

Re: New Coulomb cutoff in version 5.1

Post by Alberto Guandalini » Mon Jul 04, 2022 3:48 pm

Dear Shudong,
please see my answer in the discussion: viewtopic.php?p=12029#p12029

It applied to your problem also.

Best,
Alberto

Post Reply