HSE06@BSE

[shan dong]

Dear all,
I want to do BSE directly on top of HSE06+SOC . After HSE06 calculation, the system has an energy gap of about 0.2eV, but YAMBO identified it as a metal and reported an error in the following BSE calculation.I also encountered the same error in the calculation of PBE+U@BSE. My DFT input is as follows:

Code: Select all

&control 
    calculation='scf',
    prefix='mn',
    restart_mode='from_scratch'
    pseudo_dir = '/public1/home/scb3034/dongshan/pp/qe/sg15-lda/ONCVPSP_LDA-master/sg15_PBE_4.0.1'
    wf_collect=.true.
    nstep = 200 
    verbosity = 'high' 
    iprint = 2
/
&system
    noncolin = .true.,
    lspinorb = .true.,
    ibrav = 0,
    nat= 7,
    ntyp= 3,
    force_symmorphic=.true.
    ecutwfc = 60,
!    occupations='smearing', smearing='gaussian', degauss=0.001,
!!    nspin=2, 
    starting_magnetization(1)= 1
!    nosym = .TRUE.
    nbnd = 260,
     input_dft = 'hse',
    nqx1 = 3, nqx2 =3, nqx3 =1,
/
&electrons
 electron_maxstep = 100
 conv_thr =  1.0e-6
 diago_thr_init=5.0e-6,
 diago_full_acc=.true.
 diagonalization='david'
mixing_mode = 'plain'
 mixing_beta = 0.6
/

After performing the Yambo,I encountered the following error:

Code: Select all

[06] Dipoles
 ============

  System with reduced dimensionality
  Smallest q vectors (crystal coordinates) :
       0.083333      0.083333      0.000000
  Lenght of G vectors in each direction:     0.88381344    0.88381344    0.16624592

 [ERROR] STOP signal received while in[06] Dipoles

 [ERROR] Covariant dipoles not implemented for metals

I have attached my LOG file and input file below,Thank you~

[Davide Sangalli]

Can you attach the repot as well: r-rambo_rim* ?

Best,
D.

[shan dong]

Can you attach the repot as well: r-rambo_rim* ?

Best,
D.

Yes,Here is the associated output file.

[Daniele Varsano]

Dear Shan Dong,

it would be useful to have a look to the nscf QE output together with the r_setup from Yambo.

Best,
Daniele

[shan dong]

Dear Shan Dong,

it would be useful to have a look to the nscf QE output together with the r_setup from Yambo.

Best,
Daniele

Ok, I deleted some content to make it easier to upload.

[Daniele Varsano]

Dear Shan Dong,
there's something I do not understand. In the previous report file you post, it was indicated the grid was uniform:

Code: Select all

  X grid is uniform                                : yes

While in the r_setup it is not!

I suggest you delete the ndb.kindx file from the SAVE directory and rerun the setup using an input file (yambo.in) containing this two lines:

Code: Select all

setup
ElecTemp=0. eV

check if you obtain an uniform grid and the system is seen as semiconductor.

Best,
Daniele

[shan dong]

Dear Shan Dong,
there's something I do not understand. In the previous report file you post, it was indicated the grid was uniform:

Code: Select all

  X grid is uniform                                : yes

While in the r_setup it is not!

I suggest you delete the ndb.kindx file from the SAVE directory and rerun the setup using an input file (yambo.in) containing this two lines:

Code: Select all

setup
ElecTemp=0. eV

check if you obtain an uniform grid and the system is seen as semiconductor.

Best,
Daniele

Dear Daniele,
I have deleted the ndb.kindx and ndb.gops file from the SAVE directory and using the input you suggested above. Now the grid is uniform, but the code still recognized it as metal. It seems that the temperature setting does not work for code initialization. Even if I set the ElecTemp to zero, it still contains the temperature.

[Daniele Varsano]

Dear Shan Dong,

actually, I'm bit puzzled on what is happening here.
We need to reproduce your error, can you post a minimal example scf/nscf/psps (ie lowering the parameters in order to run in few minutes) presenting the problem.
In this way we can inspect what's happening.



Best,
Daniele

[shan dong]

Dear Shan Dong,

actually, I'm bit puzzled on what is happening here.
We need to reproduce your error, can you post a minimal example scf/nscf/psps (ie lowering the parameters in order to run in few minutes) presenting the problem.
In this way we can inspect what's happening.



Best,
Daniele

Dear Daniele,
Thank you very much for your timely reply. In fact, when I reduced my calculation parameters, HSE opened a band gap of 0.4eV,the yambo identified it as a semiconductor and BSE could operate normally. However, when I improved the calculation accuracy, HSE energy gap was reduced to 0.2eV, and YAMBO identified it as a metal. The BSE calculation starts to report an error.

[shan dong]

Dear Shan Dong,

actually, I'm bit puzzled on what is happening here.
We need to reproduce your error, can you post a minimal example scf/nscf/psps (ie lowering the parameters in order to run in few minutes) presenting the problem.
In this way we can inspect what's happening.



Best,
Daniele

Dear Daniele,
Thank you very much for your timely reply. In fact, when I reduced my calculation parameters, HSE opened a band gap of 0.4eV,the yambo identified it as a semiconductor and BSE could operate normally. However, when I improved the calculation accuracy, HSE energy gap was reduced to 0.2eV, and YAMBO identified it as a metal. The BSE calculation starts to report an error. I think YAMBO misread the Fermi level when the bandgap is relatively small, my output in QE is 4.8112eV, but yambo set the Fermi level at 5.02, which is the position of the lowest unoccupied state