[QE-users] Problems related to Hubbard potential when vc-relax is calculated

Thu Nov 23 10:04:53 CET 2023

Dear QE user,

Please sign your posts (you name and surname, affiliation).

  *   Because I beginner at Quantum Espressso, so I would appreciate it if you could explain it in as much detail as possible!!

Have a look at one of the QE schools, e.g. this one: https://indico.ictp.it/event/9616/other-view?view=ictptimetable

  *   Error in routine card_hubbard (3):
  *   Not allowed to specify two Hubbard channels that are the same for the same atom

In your input file you have this:
Jo Eu2-4f 1.0

Note that instead of "Jo" you must have "J0".

If this still does not solve all problems, try QE7.2.

  *   Can I know the psudopotential library or source including 4f-orbital of Eu atom? I couldn't find that.

Try the SSSP library: https://www.materialscloud.org/discover/sssp/table/efficiency

Also, "conv_thr = 1.0d-13" is specified in the wrong namelist. Have a look at the QE input generator: https://www.materialscloud.org/work/tools/qeinputgenerator

HTH

Iurii

----------------------------------------------------------
Dr. Iurii TIMROV
Tenure-track scientist
Laboratory for Materials Simulations (LMS)
Paul Scherrer Institut (PSI)
CH-5232 Villigen, Switzerland
+41 56 310 62 14
https://www.psi.ch/en/lms/people/iurii-timrov
________________________________
From: users <users-bounces at lists.quantum-espresso.org> on behalf of 임용식 <dydtlr5506 at gm.gist.ac.kr>
Sent: Wednesday, November 22, 2023 14:28
To: users at lists.quantum-espresso.org <users at lists.quantum-espresso.org>
Subject: [QE-users] Problems related to Hubbard potential when vc-relax is calculated

Hello,

I have a difficulty in lattice relaxing of the EuTiO3 material with Quantum Espresso 7.1 version. EuTiO3 material is antiferromagnetic. Eu atom of this material have 4f-shell electrons and spin-polarization. Hence, Hubbard potential U & Hund exchange J values are needed to do "vc-relax". Other papers also use U&J potentials for optimization of this material, and I will give an example of application in one of them.

"Density functional calculations. Our first-principles calculations were carried out using the Vienna ab-initio simulation package (VASP)47 with the Perdew–Burke–Ernzerhof approximation to the exchange correlation functional48. Eu 4f electrons were treated with the GGA+U method, using Dudarev’s approach49, with U=6.0 eV and J=1.0 eV. Default projector augmented wave pseudopotentials were employed. A plane wave cutoff of 500 eV was used and the Brillouin zone was sampled using an 8×8×6 k-point grid."

- Multiferroic quantum criticality, 2019, Multiferroic quantum criticality

I intend to follow the method of the above paper almost similarly. But instead of VASP program, I use Quantum Espresso. I couldn't search paper following the above method with Quantum Espresso.

My input data is as follows:

-------------------------------------------------------------------------------------------------------------------------------------

&control

calculation = 'vc-relax'

restart_mode='from_scratch',

prefix='ETO',

pseudo_dir ='/home/dydtlr5506/pseudo',

outdir='./wavefunc'

tstress = .true.

forc_conv_thr = 1.0d-7

dt = 20

disk_io = 'none'

nstep =9910

/

&system

ibrav= 0,

nat=20, ntyp= 4,

ecutwfc = 80.0, ecutrho = 640.0,

occupations = 'smearing',

smearing = 'gaussian'

degauss = 0.0010

nspin = 2

starting_magnetization(1)=0.5

starting_magnetization(2)=-0.5

/ &electrons

mixing_mode = 'plain'

electron_maxstep = 100

conv_thr = 1.0d-13

/

&ions

ion_dynamics = 'bfgs'

/ &cell

cell_dofree='xyz'

cell_dynamics = 'bfgs'

/

ATOMIC_SPECIES

Eu1 151.964 Eu.pbe-spn-kjpaw_psl.1.0.0.UPF

Eu2 151.964 Eu.pbe-spn-kjpaw_psl.1.0.0.UPF

Ti 47.86 Ti.pbe-spn-kjpaw_psl.1.0.0.UPF

O 15.999 O.pbe-n-kjpaw_psl.1.0.0.UPF

K_POINTS {automatic}

6 6 4 0 0 0

CELL_PARAMETERS (angstrom)

5.4810958704672510 0.0000000000000000 0.0000000000000003

0.0000000000000009 5.4810958704672510 0.0000000000000003

0.0000000000000000 0.0000000000000000 7.8763673700122299

ATOMIC_POSITIONS (crystal)

Eu1 0.0000000000000000 0.5000000000000000 0.2500000000000000 1 1 0

Eu2 0.5000000000000000 0.0000000000000000 0.2500000000000000 1 1 0

Eu1 0.5000000000000000 0.0000000000000000 0.7500000000000000 1 1 0

Eu2 0.0000000000000000 0.5000000000000000 0.7500000000000000 1 1 0

Ti 0.5000000000000000 0.5000000000000000 0.5000000000000000 1 1 0

Ti 0.0000000000000000 0.0000000000000000 0.5000000000000000 1 1 0

Ti 0.0000000000000000 0.0000000000000000 0.0000000000000000 1 1 0

Ti 0.5000000000000000 0.5000000000000000 0.0000000000000000 1 1 0

O 0.5000000000000000 0.5000000000000000 0.2500000000000000 1 1 0

O 0.0000000000000000 0.0000000000000000 0.2500000000000000 1 1 0

O 0.7079342699999996 0.2079342699999996 0.0000000000000000 1 1 0

O 0.7920657300000004 0.2920657300000004 0.5000000000000000 1 1 0

O 0.2920657300000004 0.2079342699999996 0.5000000000000000 1 1 0

O 0.2079342699999996 0.2920657300000004 0.0000000000000000 1 1 0

O 0.0000000000000000 0.0000000000000000 0.7500000000000000 1 1 0

O 0.5000000000000000 0.5000000000000000 0.7500000000000000 1 1 0

O 0.2079342699999995 0.7079342699999996 0.5000000000000000 1 1 0

O 0.2920657300000005 0.7920657300000004 0.0000000000000000 1 1 0

O 0.7920657300000004 0.7079342699999996 0.0000000000000000 1 1 0

O 0.7079342699999996 0.7920657300000004 0.5000000000000000 1 1 0

HUBBARD (ortho-atomic)

U Eu1-4f 6.0

J0 Eu1-4f 1.0

U Eu2-4f 6.0

Jo Eu2-4f 1.0

-------------------------------------------------------------------------------------------------------------------------------------

But, I checked the following error:

-------------------------------------------------------------------------------------------------------------------------------------

Error in routine card_hubbard (3):

Not allowed to specify two Hubbard channels that are the same for the same atom

-------------------------------------------------------------------------------------------------------------------------------------

Q1) Please let me know how to solve this problem.

Morever, The orbital shell of Eu atom used to Hubbard energy is 4f(since Eu orbital valency configuration: 5s2 5p6 4f7 6s2). My pseudopotential of Eu only has 5s, 5p & 6s. So. following error occurs:

-------------------------------------------------------------------------------------------------------------------------------------

Error in routine offset_atom_wfc (1):

Mismatch between the requested and available manifolds

using ibrav=0 with symmetry is DISCOURAGED, use correct ibrav instead

Eu pseudopotential contains the orbitals: 5S 6S 5P 6P 5D

Requested Hubbard manifold from the input: 4F

-------------------------------------------------------------------------------------------------------------------------------------

Q2) Can I know the psudopotential library or source including 4f-orbital of Eu atom? I couldn't find that.

Because I beginner at Quantum Espressso, so I would appreciate it if you could explain it in as much detail as possible!!

Thank you.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20231123/4f931e4c/attachment.html>