[QE-users] Problem with PBE0 calculation
Rameswar Bhattacharjee
rb1820 at georgetown.edu
Thu Jan 12 02:36:01 CET 2023
Hi Giuseppe,
Thank you very much for your detailed reply. I followed the instructions
and was able to complete the SCF calculation. Also, I did an NSCF
calculation using the same combination you suggested as a pre-step to
perform the band calculation. My ultimate aim is to get the band gap using
a hybrid functional such as PBE0.
However, I am not able to run the band calculation with this combination
got an error like below:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine exx_grid_init (1):
wrong EXX q grid
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
It seems the k-points grid I am using is not suitable for EXX calculation
although I used the same grid for PBE and it was perfect. I am sure someone
in the forum had performed band structure using hybrid functional and would
be able to help me resolve this. Any help would be highly appreciated.
Here is my input for band calculation using PBE0
------------------------------------------
&control
restart_mode='from_scratch'
calculation='bands'
prefix='Ethyne-Anthracene',
pseudo_dir = '/home/rb1820/QE-PP/NC',
outdir='./scratch'
/
&system
ibrav = 0,
tot_charge=0,
nat=36,
ntyp=2,
ecutwfc = 90,
ecutfock= 150,
input_dft='pbe0'
vdw_corr='grimme-d2',
nbnd = 60
/
&electrons
electron_maxstep = 1000
mixing_beta=0.7
diagonalization='david'
diago_david_ndim = 2
conv_thr=1.0d-8
/
&ions
/
&CELL
cell_dynamics='bfgs',
press = 0.0
cell_dofree = 'x',
/
ATOMIC_SPECIES
H 1.008 H_ONCV_PBE-1.2.upf
C 12.0107 C_ONCV_PBE-1.2.upf
ATOMIC_POSITIONS {angstrom}
K_POINTS { crystal }
11
-0.5 0.0 0.0 1.0
-0.4 0.0 0.0 1.0
-0.3 0.0 0.0 1.0
-0.2 0.0 0.0 1.0
-0.1 0.0 0.0 1.0
0.0 0.0 0.0 1.0
0.1 0.0 0.0 1.0
0.2 0.0 0.0 1.0
0.3 0.0 0.0 1.0
0.4 0.0 0.0 1.0
0.5 0.0 0.0 1.0
CELL_PARAMETERS {angstrom}
6.933462797 0.000000000 0.000000000
0.000000000 20.000000000 0.000000000
0.000000000 0.000000000 20.000000000
---------------------------------------------------------------
Thanks
Rameswar Bhattacharjee
Georgetown University
On Wed, Jan 11, 2023 at 3:21 AM Giuseppe Mattioli <
giuseppe.mattioli at ism.cnr.it> wrote:
>
> Dear Rameswar Bhattacharjee
> I don't know if this is the actual source of error, but I strongly
> recommend to use norm-conserving pseudopotentials when performing EXX
> calculations. You have generally no speed-up with US because ecutrho
> is more or less often the same, and in your case you are using
> tremendously high (and likely useless) values for ecutwfc and ecutrho.
> Moreover, using NC you can finely tune the density basis set used to
> build Fock integrals with ecutfock, otherwise stuck to the ecutrho
> value. This combination of values is probably responsible for a very
> high memory request (the code prints an estimate at the beginning of
> the output). For example, *using C and H ONCV pseudopotentials*, you
> should be on the reasonably accurate side using
>
> ecutwfc=90.0
> ecutfock=135.0~180.0
> ecutrho is automatically fixed at ecutwfc*4=360.0 in the case of NC
>
> HTH
> Giuseppe
>
> Quoting Rameswar Bhattacharjee <rb1820 at georgetown.edu>:
>
> > Hi Everyone,
> > I am trying to get a band structure using a hybrid functional. As
> suggested
> > previously in this forum I choose PBE0 functional with pbe-ultrasoft
> > pseudopotential. The calculation starts fine and scf iteration converges
> > smoothly. But the job is stuck and does not complete with the last line
> "ACE
> > projected onto 60 (nbndproj) and applied to 60 (nbnd) bands". I am
> > not sure what mistake I am making here or if it is just a memory issue as
> > no error message is printing. Any suggestion would be highly
> appreciated. I
> > am providing last few lines of the output and my input str for reference.
> > Thank you.
> >
> > Last few lines of the scf output
> > -------------------------------
> >
> > highest occupied, lowest unoccupied level (ev): -3.5627 -3.2294
> >
> >
> > ! total energy = -312.15802972 Ry
> >
> > estimated scf accuracy < 3.2E-09 Ry
> >
> >
> > convergence has been achieved in 12 iterations
> >
> >
> > Using ACE for calculation of exact exchange
> >
> >
> > EXX grid: 4188907 G-vectors FFT dimensions: ( 100, 288, 288)
> >
> > ACE projected onto 60 (nbndproj) and applied to 60 (nbnd)
> bands
> > ----------------------------------
> >
> > Input str
> > ------------------------------
> >
> > &control
> >
> > restart_mode='from_scratch'
> >
> > calculation='scf'
> >
> > prefix='Test',
> >
> > pseudo_dir = '/home/QE-PP',
> >
> > outdir='./scratch'
> >
> > /
> >
> > &system
> >
> > ibrav = 0,
> >
> > tot_charge=0,
> >
> > nat=36,
> >
> > ntyp=2,
> >
> > ecutwfc = 140,
> >
> > ecutrho = 1400.0,
> >
> > input_dft='pbe0'
> >
> > vdw_corr='grimme-d2',
> >
> > nbnd = 60
> >
> > /
> >
> > &electrons
> >
> > electron_maxstep = 1000
> >
> > mixing_beta=0.7
> >
> > diagonalization='david'
> >
> > diago_david_ndim = 2
> >
> > conv_thr=1.0d-8
> >
> > /
> >
> > &ions
> >
> > /
> >
> > &CELL
> >
> > cell_dynamics='bfgs',
> >
> > press = 0.0
> >
> > cell_dofree = 'x',
> >
> > /
> >
> > ATOMIC_SPECIES
> >
> > H 1.008 H.pbe-rrkjus_psl.1.0.0.UPF
> >
> > C 12.0107 C.pbe-n-rrkjus_psl.1.0.0.UPF
> >
> >
> > ATOMIC_POSITIONS {angstrom}
> >
> >
> > K_POINTS automatic
> >
> > 12 1 1 0 0 0
> >
> >
> > CELL_PARAMETERS {angstrom}
> >
> > 6.933462797 0.000000000 0.000000000
> >
> > 0.000000000 20.000000000 0.000000000
> >
> > 0.000000000 0.000000000 20.000000000
> >
> > ----------------
> >
> >
> > Rameswar Bhattacharjee
> >
> > Georgetown University
>
>
>
> GIUSEPPE MATTIOLI
> CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
> Via Salaria Km 29,300 - C.P. 10
> I-00015 - Monterotondo Scalo (RM)
> Mob (*preferred*) +39 373 7305625
> Tel + 39 06 90672342 - Fax +39 06 90672316
> E-mail: <giuseppe.mattioli at ism.cnr.it>
>
> _______________________________________________
> The Quantum ESPRESSO community stands by the Ukrainian
> people and expresses its concerns about the devastating
> effects that the Russian military offensive has on their
> country and on the free and peaceful scientific, cultural,
> and economic cooperation amongst peoples
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20230111/e84f7d4e/attachment.html>
More information about the users
mailing list