It is true, in principle you can use whatever PP and overrule the xc
functional using "input_dft". However, it is intuitively wise (and can
be confirmed doing a few simple tests in simple systems against
well-converged all-electron calculations) to use PPs generated using
an xc functional as close as possible to the hybrid functional. For
example, in the case of PBE0 you have 75% of PBE exchange and 100% of
PBE correlations, so that it is reasonable to use PBE PPs. The same
holds for B3LYP and BLYP.
HTH
Giuseppe
Quoting Abdeslam Houari via users <users@lists.quantum-espresso.org>:
When you use "input_dft", this automatically overwrite the
xc-functional of the PP (this is well explained in the PWscf
manuel). As far as I understood (we discussed this few weeks ago in
the forum), whatever the PP you are using, the "input_dft" will run
hybrid calculation according to it's functional definition and
discard the PP (For example PBE0: 1/4 EXX and (3/4 E_X + E_C) at the
PBE level). If that's true, this means that you can use any PP.
I hope this is helpful
=========================================
Dr. Abdesalem
HOUARI-------------------------------------------------------------------------------------------
Department of physics, Theoretical Physics Laboratory
University of Bejaia-06000. Algeria.
E-mail: abdeslam.hou...@univ-bejaia.dz & habds...@yahoo.fr
https://sites.google.com/site/houariabdeslam/homepage
=========================================
On Saturday, 7 January 2023 at 01:33:40 am GMT+1, Rameswar
Bhattacharjee <rb1...@georgetown.edu> wrote:
Hi Giuseppe,Thank you very much for sharing the input sample and
your valuable suggestion. I will try to run a calculation with
B3LYP/PBE0 and will see how it goes.
Rameswar
On Fri, Jan 6, 2023 at 1:58 PM Giuseppe Mattioli
<giuseppe.matti...@ism.cnr.it> wrote:
Dear Simon
The lack of pseudopotentials generated using a hybrid functional does
not represent a significant source of error when using such
functionals in calculations. I've run tons of B3LYP calculations using
BLYP pseudopotentals and of PBE0 or HSE calculations using PBE
pseudopotentials. PBE PPs are easier to find, while BLYP ones may be
more difficult and sometimes you must (re)generate them yourself.
The input should be something like this (but check all the options in
the pw input guide as they may be suitable/not suitable for your
calculations):
&control
calculation = 'relax'
restart_mode='from_scratch',
prefix='$FILE',
pseudo_dir = '$PSEUDO_DIR/',
outdir='$TMP_DIR/',
nstep=200,
/
&system
ibrav=1, celldm(1)=40.0000,
nat=87 ntyp=4,
ecutwfc=90.0,
ecutfock=130.0,
occupations='smearing', degauss=0.01,
nspin=1,
input_dft='b3lyp'
vdw_corr='grimme-d3',
/
&electrons
diagonalization='david',
mixing_mode='plain',
mixing_beta=0.1,
conv_thr=1.0d-6,
electron_maxstep=100
adaptive_thr=.true.
/
&ions
ion_dynamics='bfgs'
/
ATOMIC_SPECIES
O 15.999 O.blyp-mt.UPF
N 14.007 N.blyp-mt.UPF
C 12.011 C.blyp-mt.UPF
H 1.008 H.blyp-vbc.UPF
ATOMIC_POSITIONS {angstrom}
...
K_POINTS {gamma}
NB: I always recommend the use of norm-conserving pseudopotentials (in
this case they are rather old but very well tested pseudopotentials
that used to be in the QE repo, but you can generate BLYP PPs using
the "atomic" ld1.x code and the PSlibrary, or even the ONCV generation
code) when performing EXX calculations.
HTH
Giuseppe
Quoting Rameswar Bhattacharjee <rb1...@georgetown.edu>:
Hi Simon,
Thank you for the information. I have gone through the input_dft and it
looks like I can use PBE0 or B3LYP. But I am not sure for that case which
pseudopotential I should use. Could you (or anyone) have a sample input to
run a QUE calculation using the B3LYP functional? That would be very
helpful. Thank you
Rameswar
On Fri, Jan 6, 2023 at 11:34 AM Simon Imanuel Rombauer <
simon.romba...@student.uni-augsburg.de> wrote:
Hello Rameswar,
see 'input_dft' option in the documentation, see Modules/funct.f90 for
possible functionals.
Best,
Simon
Am Freitag, Januar 06, 2023 17:00 CET, schrieb Rameswar Bhattacharjee <
rb1...@georgetown.edu>:
> Hi Everyone,
> I wonder if I can use hybrid functionals such as PBE0 or B3LYP in QE for
> ground state calculation. All the pseudopotentials I found on the website
> are for PBE. But I need an exchange-correlation functional (not pure) to
> calculate the band gap more accurately.
>
> Any suggestions would be appreciated. Thank you.
>
> Rameswar Bhattacharjee
> PostDoc
> Georgetown University
_______________________________________________
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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@lists.quantum-espresso.org
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_______________________________________________
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@lists.quantum-espresso.org
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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.matti...@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@lists.quantum-espresso.org
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