[QE-users] second step of scf in relax calculations didn't converge
Giuseppe Mattioli
giuseppe.mattioli at ism.cnr.it
Wed Jul 1 20:02:26 CEST 2020
Into the &electrons namelist
Best
G.
Quoting Coralie Khabbaz <khabbaz.coralie at gmail.com>:
> Hello Giuseppe,
>
> where exactly should I include the switch?
> Thank you!
> ------------------------------
> *From:* users <users-bounces at lists.quantum-espresso.org> on behalf of
> Giuseppe Mattioli <giuseppe.mattioli at ism.cnr.it>
> *Sent:* Wednesday, July 1, 2020 12:36:14 PM
> *To:* Quantum ESPRESSO users Forum <users at lists.quantum-espresso.org>
> *Subject:* Re: [QE-users] second step of scf in relax calculations didn't
> converge
>
>
> A simpler but often effective trick: sometimes at (or after) the first
> step your system may be trapped in an unlucky configuration that
> prevent convergence of the scf iteration. You can either do as Matteo
> says, or try (after inspecting the geometry of the second step to be
> sure that your system isn't going bananas) to use the switch
> scf_must_converge=.false.
> Such switch forces the bfgs step even if the wfc is not fully
> converged, and it is sensible only if your wfc is not very far from
> convergence and in the initial steps of a 'relax' calculation. If you
> are lucky, in a few steps you jump out of your "Bermuda triangle" and
> further steps converge in a smoother way.
> HTH
> Giuseppe
>
> Quoting Coralie Khabbaz <khabbaz.coralie at gmail.com>:
>
>> Hello Matteo,
>>
>> Thank you so much for your reply. I didn't understand what do you mean by
>> initial trust radius? Also, at first my convergence threshold was at 1^-6
>> but the first scf step didn't converge in 1000 steps. Then, I fixed it at
>> 1^-4 and the first step converged. So do you think I should tighten it? I
>> didn't try starting a new scf from the new iconic positions because I
> don't
>> know how to.
>>
>> This is my input file:
>>
>> &CONTROL
>> calculation = "relax"
>> forc_conv_thr = 1.00000e-03
>> max_seconds = 4.32000e+05
>> nstep = 300
>> pseudo_dir =
> "/home/coralee/projects/def-jkopysci/coralee/.pseudopot"
>> /
>>
>> &SYSTEM
>> a = 8.32716e+00
>> angle1(1) = 0.00000e+00
>> angle1(2) = 0.00000e+00
>> angle2(1) = 0.00000e+00
>> angle2(2) = 0.00000e+00
>> b = 8.98689e+00
>> c = 2.52767e+01
>> cosab = 6.12323e-17
>> cosac = 6.12323e-17
>> cosbc = -1.85547e-01
>> degauss = 2.00000e-02
>> ecutrho = 4.75221e+02
>> ecutwfc = 5.03902e+01
>> ibrav = 14
>> nat = 48
>> nbnd = 490
>> nspin = 2
>> ntyp = 2
>> occupations = "smearing"
>> smearing = "gaussian"
>> starting_magnetization(1) = 2.00000e-01
>> starting_magnetization(2) = 2.00000e-01
>> /
>>
>> &ELECTRONS
>> conv_thr = 1.00000e-04
>> diagonalization = "david"
>> electron_maxstep = 1000
>> mixing_beta = 1.00000e-01
>> mixing_mode = "local-TF"
>> startingpot = "atomic"
>> startingwfc = "atomic+random"
>> /
>>
>> &IONS
>> ion_dynamics = "bfgs"
>> /
>>
>> &CELL
>> /
>>
>> K_POINTS {automatic}
>> 2 2 1 0 0 0
>>
>> ATOMIC_SPECIES
>> N 14.00674 N.pbe-n-kjpaw_psl.1.0.0.UPF
>> W 183.84000 W.pbe-spn-kjpaw_psl.1.0.0.UPF
>>
>> ATOMIC_POSITIONS {angstrom}
>> N 3.207882 2.672960 14.837784
>> N 7.371462 2.672960 14.837784
>> N 3.207882 -1.820484 14.837784
>> N 7.371462 -1.820484 14.837784
>> W 3.207882 4.882815 14.748648
>> W 7.371462 4.882815 14.748648
>> W 3.207882 0.389371 14.748648
>> W 7.371462 0.389371 14.748648
>> N 1.126093 5.365612 14.468179
>> N 5.289672 5.365612 14.468179
>> N 1.126093 0.872168 14.468179
>> N 5.289672 0.872168 14.468179
>> W 1.126093 3.038143 14.415413
>> W 5.289672 3.038143 14.415413
>> W 1.126093 -1.455301 14.415413
>> W 5.289672 -1.455301 14.415413
>> N 3.207882 5.336567 12.630078
>> N 7.371462 5.336567 12.630078
>> N 3.207882 0.843123 12.630078
>> N 7.371462 0.843123 12.630078
>> W 3.207882 3.052977 12.540942
>> W 7.371462 3.052977 12.540942
>> W 3.207882 -1.440467 12.540942
>> W 7.371462 -1.440467 12.540942
>> N 1.126093 3.535775 12.260473
>> N 5.289672 3.535775 12.260473
>> N 1.126093 -0.957669 12.260473
>> N 5.289672 -0.957669 12.260473
>> W 1.126093 5.701750 12.207706
>> W 5.289672 5.701750 12.207706
>> W 1.126093 1.208305 12.207706
>> W 5.289672 1.208305 12.207706
>> N 3.207882 3.506729 10.422372 0 0 0
>> N 7.371462 3.506729 10.422372 0 0 0
>> N 3.207882 -0.986715 10.422372 0 0 0
>> N 7.371462 -0.986715 10.422372 0 0 0
>> W 3.207882 5.716584 10.333236 0 0 0
>> W 7.371462 5.716584 10.333236 0 0 0
>> W 3.207882 1.223140 10.333236 0 0 0
>> W 7.371462 1.223140 10.333236 0 0 0
>> N 1.126093 6.199382 10.052766 0 0 0
>> N 5.289672 6.199382 10.052766 0 0 0
>> N 1.126093 1.705938 10.052766 0 0 0
>> N 5.289672 1.705938 10.052766 0 0 0
>> W 1.126093 3.871912 10.000000 0 0 0
>> W 5.289672 3.871912 10.000000 0 0 0
>> W 1.126093 -0.621532 10.000000 0 0 0
>> W 5.289672 -0.621532 10.000000 0 0 0
>>
>> On Wed, 1 Jul 2020 at 10:48, Matteo Cococcioni <matteo.cococcioni at unipv.it
>>
>> wrote:
>>
>>> Hello,
>>>
>>> it's very difficult to guess what is wrong in your input if you don't
> show
>>> it.
>>> In any case, if you have converged forces and stresses on cut-off(s) and
>>> number of k-points/smearing, it might be a good idea to tighten your
>>> convergence threshold and reduce the initial trust radius. Maybe your
>>> forces and stresses are so loosely converged and your ionic/cell step so
>>> big that the system moves to a configuration that is difficult to
> converge.
>>> Or maybe your starting lattice parameter/ionic configuration are very far
>>> from equilibrium and the system tries to make a big jump at the
> beginning.
>>> Also, have you tried to start a new scf from the new ionic position?
>>>
>>> Please add your affiliation
>>>
>>> Regards,
>>>
>>> Matteo
>>>
>>> Il giorno mer 1 lug 2020 alle ore 13:45 Coralie Khabbaz <
>>> khabbaz.coralie at gmail.com> ha scritto:
>>>
>>>> Hello,
>>>>
>>>> I am doing a relax calculation on my WN (48 atoms) slab. The first step
>>>> of scf calculations converged but then the second step didn't converge
> in
>>>> 1000 steps (which was my limit). So, the calculations stopped, and I got
>>>> many files (data-file.xml, charge-density.dat, paw.txt,
>>>> spin-polarization.dat...) but no output file. If my first scf step
>>>> converged doesn't that mean that all of my other scf steps should
> converge
>>>> but need more steps? Or is there a problem in my input file?
>>>> _______________________________________________
>>>> 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
>>>
>>>
>>>
>>> --
>>> Matteo Cococcioni
>>> Department of Physics
>>> University of Pavia
>>> Via Bassi 6, I-27100 Pavia, Italy
>>> tel +39-0382-987485
>>> e-mail matteo.cococcioni at unipv.it <lucio.andreani at unipv.it>
>>> _______________________________________________
>>> 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
>
>
>
> GIUSEPPE MATTIOLI
> CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
> Via Salaria Km 29,300 - C.P. 10
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> Mob (*preferred*) +39 373 7305625
> Tel + 39 06 90672342 - Fax +39 06 90672316
> E-mail: <giuseppe.mattioli at ism.cnr.it>
>
> _______________________________________________
> 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
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>
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