[QE-users] non-convergency of DFPT+U calculation
Merlin Meheut
merlin.meheut at gmail.com
Wed Mar 4 17:32:47 CET 2020
Dear Iurii,
I learned a lot with your guidance, thank you so much! Unfortunately, I am
afraid that none of your propositions (use SSSP pseudopotentials, change
density cutoff) did solve the matter (1). To further explore this question,
I also did DFPT+U phonon calculation on FeO (2), with an input almost
identical to your example02 on NiO, and there was a divergence for the
second representation, very similar to what I have for Fe2SiO4. At last
(3), I tried to compute the +U value based on your example02 as well. For
fayalite, I succeeded to compute U for 1x1x1 q-point grid, but 2x1x2 and
2x2x2 grids failed. For FeO, the situation is more complex, depending on
the k-point grid and on the q-point grid, sometimes it works, sometimes it
does not converge, sometimes it crashes. But generally for large grids it
is not possible to reach the end of the calculation. Below are more
detailed descriptions of these problems:
The procedures were tested for pseudopotentials
O.pz-n-rrkjus_psl.0.1.UPF + Fe.pz-spn-rrkjus_psl.0.2.1.UPF +
Si.pz-n-rrkjus_psl.0.1.UPF
Fe.pbesol-spn-kjpaw_psl.0.2.1.UPF + Si.pbesol-n-rrkjus_psl.1.0.0.UPF +
O.pbesol-n-kjpaw_psl.0.1.UPF
and the formerly described pseudopotentials
(1) For DFPT+U phonon calculations on Fayalite, I followed your suggestion
to adopt the approach described in example 02, with a first scf calculation
in the metallic state:
&system
(...)
nspin=2,
occupations='smearing',
degauss=0.001,
smearing= 'gauss',
starting_magnetization(1)=0.5,
starting_magnetization(2)=-0.5,
lda_plus_u = .true.,
lda_plus_u_kind = 0,
U_projection_type = 'ortho-atomic',
Hubbard_U(1)=2.5,
Hubbard_U(2)=2.5,
/&end
&electrons
electron_maxstep = 200,
conv_thr = 1.d-10,
mixing_beta = 0.4,
/&end
(...)
K_POINTS {automatic}
2 2 2 1 1 1
and a second calculation as insulating material:
&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,
nbnd=${nstates},
nspin=2,
occupations='fixed',
tot_magnetization= 0,
lda_plus_u = .true.,
lda_plus_u_kind = 0,
U_projection_type = 'atomic',
Hubbard_U(1)=2.5,
Hubbard_U(2)=2.5,
/&end
&electrons
electron_maxstep = 200,
conv_thr = 1.d-15,
mixing_mode = 'plain',
mixing_beta = 0.4,
startingpot = 'file',
startingwfc = 'file',
/&end
followed by the phonon calculation:
Liz m1
&inputph
alpha_mix(1) = 0.3,
tr2_ph = 1.0D-17,
prefix='FAYA2',
fildyn='mat.$PREFIX',
lraman=.false.,
epsil =.false.,
trans =.true.,
zue = .false.,
zeu= .false.,
start_irr=23,
last_irr=23,
niter_ph=20,
outdir ='./',
/&end
0.0 0.0 0.0
The procedure was tested for pseudopotentials
O.pz-n-rrkjus_psl.0.1.UPF + Fe.pz-spn-rrkjus_psl.0.2.1.UPF +
Si.pz-n-rrkjus_psl.0.1.UPF
Fe.pbesol-spn-kjpaw_psl.0.2.1.UPF + Si.pbesol-n-rrkjus_psl.1.0.0.UPF +
O.pbesol-n-kjpaw_psl.0.1.UPF
and the formerly described
I also changed cutoffs as you suggested. There is no difference that I can
see in the result.
(2) For DFPT+U phonon calculations on FeO, I adopted the same approach,
with two scf calculations very similar to the one shown in HP example02,
except for U_projection_type = 'atomic', instead of 'ortho-atomic' for the
second scf . The following phonon input looks like this:
Liz m1
&inputph
alpha_mix(1) = 0.3,
tr2_ph = 1.0D-15,
(...)
lraman=.false.,
epsil =.false.,
trans =.true.,
zue = .false.,
zeu= .false.,
start_irr=2,
last_irr=2,
niter_ph=20,
/&end
0.0 0.0 0.0
Here also, we obtain a very clear divergence, whatever the Fe and O
pseudopotentials considered above.
(3) Then I tried to compute the value of the +U parameter, based on your HP
example02. I did it for fayalite and for FeO (in which case the input is
essentially the same than example02, except for the pseudopotentials).
Following your article (Timrov et al 2018, PRB 98, 085127), I tried
different values for the k-point and q-point grids . Some work, some do not
converge, some diverge. For fayalite, it was only possible to converge for
1x1x1 q-point grid. For FeO as well, large grids tend to be just impossible
to complete, as some particular q-points do not converge. Once again,
whatever the pseudo or the cutoff. However, these are not exactly the same
configurations that fail depending on the pseudopotentials.
If you have any hints that may permit to progress on those issues that
would be awesome!
Best regards,
Merlin
--
Merlin Méheut
adresse labo:
GET - OMP - Université Paul Sabatier
14 avenue Edouard Belin
31400 Toulouse
FRANCE
tel: (+33) 5 61 33 26 17
http://www3.obs-mip.fr/get/profils/Meheut_Merlin
Le jeu. 20 févr. 2020 à 10:05, Timrov Iurii <iurii.timrov at epfl.ch> a écrit :
> Dear Merlin,
>
>
> By the way, since you are using DFPT+U to compute phonons including the
> Hubbard U correction, I would like to let you (and others) know that the
> paper describing DFPT+U has been just published in Physical Review B:
>
> A. Floris, I. Timrov, B. Himmetoglu, N. Marzari, S. de Gironcoli, and M.
> Cococcioni, "Hubbard-corrected density functional perturbation theory
> with ultrasoft pseudopotentials", Phys. Rev. B 101, 064305 (2020). Best
> regards,
>
> 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
> Timrov Iurii <iurii.timrov at epfl.ch>
> *Sent:* Wednesday, February 19, 2020 10:05:01 AM
> *To:* Quantum ESPRESSO users Forum
> *Subject:* Re: [QE-users] non-convergency of DFPT+U calculation
>
>
> Dear Merlin,
>
>
> Total magnetization must be zero for an antiferromagnetic insulator.
> Hence, some deviation from zero that you obtain is probably a numerical
> noise (I would check the convergence of the results: reduce conv_thr,
> increase the size of the k mesh, etc., and relax well the structure).
>
>
> > If I wanted to be closer to the smearing calculation, I would have to
> consider nocolin=.true., is that right?
>
>
> DFPT+U with noncolin=.true. is not implemented.
>
>
> 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:* Wednesday, February 19, 2020 12:38:08 AM
> *To:* Quantum ESPRESSO users Forum
> *Subject:* Re: [QE-users] non-convergency of DFPT+U calculation
>
> Dear Iurii,
>
> Thank you again for your help! So far, the Example02 seems quite clear to
> me, although it will take me some time to apply it to my system and check
> that everything is working. One quick question, though: in my case, the
> "total magnetization" obtained from the first calculation (with smearing)
> is non-zero and non-integer: "total magnetization = -0.63 Bohr
> mag/cell" (which makes sense since I have two different sites). As I
> understand it, for the second calculation, the variable tot_magnetization
> should be integer, so I can only take it equal to 0 or 1 here (I tried with
> 0, I don't know which is better). If I wanted to be closer to the smearing
> calculation, I would have to consider nocolin=.true., is that right?
>
> Greetings,
>
> Merlin
>
> Le mar. 18 févr. 2020 à 17:32, Timrov Iurii <iurii.timrov at epfl.ch> a
> écrit :
>
>> 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> 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> on behalf of
>>> Merlin Meheut <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.: 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.: 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.: 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.: 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.: 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.: 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.: 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.: 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.: 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.: 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
>>>
>>> _______________________________________________
>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso
>>> )
>>> users mailing list users at lists.quantum-espresso.org
>>> https://lists.quantum-espresso.org/mailman/listinfo/users
>>
>>
>>
>> --
>> Merlin Méheut
>> adresse labo:
>> GET - OMP - Université Paul Sabatier
>> 14 avenue Edouard Belin
>> 31400 Toulouse
>> FRANCE
>> tel: (+33) 5 61 33 26 17
>>
>> _______________________________________________
>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
>> users mailing list users at lists.quantum-espresso.org
>> https://lists.quantum-espresso.org/mailman/listinfo/users
>
>
>
> --
> Merlin Méheut
> adresse labo:
> GET - OMP - Université Paul Sabatier
> 14 avenue Edouard Belin
> 31400 Toulouse
> FRANCE
> tel: (+33) 5 61 33 26 17
>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
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