[QE-users] non-convergency of DFPT+U calculation
Timrov Iurii
iurii.timrov at epfl.ch
Tue Feb 18 17:31:57 CET 2020
Dear Merlin,
> Does that mean that magnetic insulators cannot be treated by Quantum Espresso?
It is possible to model magnetic insulators in Quantum ESPRESSO. I am using the procedure described in q-e-qe-6.5/HP/examples/example02/README. If the description in README file is not clear enough, please let me know.
Greetings,
Iurii
--
Dr. Iurii Timrov
Postdoctoral Researcher
STI - IMX - THEOS and NCCR - MARVEL
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: users <users-bounces at lists.quantum-espresso.org> on behalf of Merlin Meheut <merlin.meheut at gmail.com>
Sent: Tuesday, February 18, 2020 5:21:46 PM
To: Quantum ESPRESSO users Forum
Subject: Re: [QE-users] non-convergency of DFPT+U calculation
Hi Iurii,
First thank you very much for this remark, I did not know that one could not use tot_magnetization and starting_magnetization together. Indeed, this is reported in the Documentation INPUT_PW.def.
At this point, however, I don't see how to make an input for an antiferromagnetic insulating material (which is the goal here). Because with this input, the state is non magnetic:
&system
ibrav =8, celldm(1)=9.107535, celldm(2)=2.17425,
celldm(3)=1.263056,
nat =28, ntyp = 4, ecutwfc =80.0, ecutrho = 320.0,
nspin=2, tot_magnetization=0,
lda_plus_u = .true., U_projection_type = 'atomic',
Hubbard_U(1)=2.4, Hubbard_U(2)=2.6, ! valeurs Yu et al 2013 =2.4/2.6
/&end
And if you use this input:
&system
ibrav =8, celldm(1)=9.107535, celldm(2)=2.17425,
celldm(3)=1.263056,
nat =28, ntyp = 4, ecutwfc =${a}.0, ecutrho = ${b}.0,
nspin=2,
starting_magnetization(1)=0.5, starting_magnetization(2)=-0.5,
lda_plus_u = .true., U_projection_type = 'atomic',
Hubbard_U(1)=2.5, Hubbard_U(2)=2.5,
/&end
,you have an error message:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Error in routine iosys (1):
fixed occupations and lsda need tot_magnetization
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
So as you say, using starting_magnetization imposes using smearing. But if I am correct, smearing means that your material is metallic, and therefore you cannot compute dielectric quantities or effective charges with phonon. Actually, in the INPUT_PW.def file, the word "antiferromagnetic" is only present once, in the "starting_magnetization" definitions. Does that mean that magnetic insulators cannot be treated by Quantum Espresso?
Would you have any hint as to how to extract myself from such a dead end?
Thanks again for your help,
Greetings,
Merlin
Le dim. 16 févr. 2020 à 23:11, Timrov Iurii <iurii.timrov at epfl.ch<mailto:iurii.timrov at epfl.ch>> a écrit :
Dear Merlin,
In your input for the PW calculation you have:
> tot_magnetization=0,
> starting_magnetization(1)=0.5, starting_magnetization(2)=-0.5
tot_magnetization and starting_magnetization must not be used together (please check the documentation). Moreover, starting_magnetization must be used with occupations='smearing', but I do not see smearing in your input. Is the ground state metallic or insulating?
How many representations do you have in total? And only #23 diverges?
Not sure this will help, but you may try to use dual = ecutrho/ecutwfc = 12, with ecutwfc=80 Ry.
> Si 27.9769 Si.pz2.UPF
> O 15.9949 O.pz.UPF
I do not know what are these pseudos, and how good/bad are they. You can try to check the SSSP library.
> Fe1 55.9349 Fe.pz-n-rrkjus_psl.1.0.0.UPF
> Fe2 55.9349 Fe.pz-n-rrkjus_psl.1.0.0.UPF
Also for these I would check the SSSP library.
Greetings,
Iurii
--
Dr. Iurii Timrov
Postdoctoral Researcher
STI - IMX - THEOS and NCCR - MARVEL
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: users <users-bounces at lists.quantum-espresso.org<mailto:users-bounces at lists.quantum-espresso.org>> on behalf of Merlin Meheut <merlin.meheut at gmail.com<mailto:merlin.meheut at gmail.com>>
Sent: Sunday, February 16, 2020 9:22:57 PM
To: Quantum Espresso users Forum
Subject: [QE-users] non-convergency of DFPT+U calculation
Dear PWSCF users,
I am trying to realize a phonon calculation (at gamma) with +U on fayalite (olivine structure Fe2SiO4) with anti-ferromagnetic configuration , and whether the calculation goes fine without +U, I have one representation (#23) that systematically fails to converge when I add a +U. I tried several values for the +U (0.5, 2.5, 4), several functionals (PZ, PBE), but the result is always the same. I have used QE versions 6.4 and 6.4.1 on two different computing centers . Would you have any idea about the reasons for such a failure? I am specifically worried by one output message: "Atomic wfc used for the DFT+U projector are NOT orthogonalized", but I don't know how to fix that.
Here are examples of my scf and ph inputs, and the failing ph output:
scf:
&control
calculation = 'scf',
(...)
tprnfor = .true.,
tstress = .true.,
/&end
&system
ibrav =0, celldm(1)=9.107535,
nat =28, ntyp = 4, ecutwfc =80.0, ecutrho = 320.0,
nspin=2, tot_magnetization=0,
starting_magnetization(1)=0.5, starting_magnetization(2)=-0.5,
lda_plus_u = .true., U_projection_type = 'atomic',
Hubbard_U(1)=2.4, Hubbard_U(2)=2.6
/&end
&electrons
electron_maxstep = 150,
conv_thr = 1.d-11,
mixing_mode = 'plain',
startingwfc = 'atomic',
mixing_beta = 0.3,
/&end
ATOMIC_SPECIES
Fe1 55.9349 Fe.pz-n-rrkjus_psl.1.0.0.UPF
Fe2 55.9349 Fe.pz-n-rrkjus_psl.1.0.0.UPF
Si 27.9769 Si.pz2.UPF
O 15.9949 O.pz.UPF
(...)
ph input:
&inputph
amass(1)=55.9349,
amass(2)=55.9349,
amass(3)=27.9769,
amass(4)=15.9949,
alpha_mix(1) = 0.5,
! ldisp=.true., nq1=2, nq2=2, nq3=2,
tr2_ph = 1.0D-17,
prefix='FAYA2',
fildyn='mat.$PREFIX',
lraman=.false.,
epsil =.false.,
trans =.true.,
zue = .false.,
zeu= .false.,
start_irr=23,
last_irr=23,
outdir ='./',
/&end
0.0 0.0 0.0
ph output:
Representation # 23 mode # 23
Self-consistent Calculation
iter # 1 total cpu time : 58.7 secs av.it<http://av.it>.: 8.5
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 1.045E-06
iter # 2 total cpu time : 62.9 secs av.it<http://av.it>.: 23.0
thresh= 1.022E-04 alpha_mix = 0.500 |ddv_scf|^2 = 2.668E-04
iter # 3 total cpu time : 66.4 secs av.it<http://av.it>.: 17.5
thresh= 1.633E-03 alpha_mix = 0.500 |ddv_scf|^2 = 3.033E-03
iter # 4 total cpu time : 69.0 secs av.it<http://av.it>.: 11.0
thresh= 5.508E-03 alpha_mix = 0.500 |ddv_scf|^2 = 5.602E-02
iter # 5 total cpu time : 73.0 secs av.it<http://av.it>.: 15.5
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 1.238E+00
iter # 6 total cpu time : 76.7 secs av.it<http://av.it>.: 19.5
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 2.841E+01
iter # 7 total cpu time : 80.9 secs av.it<http://av.it>.: 23.0
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 6.534E+02
iter # 8 total cpu time : 85.3 secs av.it<http://av.it>.: 24.5
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 1.446E+04
iter # 9 total cpu time : 90.1 secs av.it<http://av.it>.: 27.5
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 3.214E+05
iter # 10 total cpu time : 95.5 secs av.it<http://av.it>.: 30.0
thresh= 1.000E-02 alpha_mix = 0.500 |ddv_scf|^2 = 7.200E+06
(.....)
Thank you in advance for your help! Feel free to ask for any further calculation details.
Regards,
--
Merlin Méheut
adresse labo:
GET - OMP - Université Paul Sabatier
14 avenue Edouard Belin
31400 Toulouse
FRANCE
tel: (+33) 5 61 33 26 17
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--
Merlin Méheut
adresse labo:
GET - OMP - Université Paul Sabatier
14 avenue Edouard Belin
31400 Toulouse
FRANCE
tel: (+33) 5 61 33 26 17
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