[Pw_forum] Problems Computing Cholesky for VC-Relax of MnO2
Paolo Giannozzi
p.giannozzi at gmail.com
Fri Sep 15 18:09:19 CEST 2017
It's horribly slow to converge but it didn't give any "Cholesky error" to
me in a quick test
Paolo
On Tue, Sep 12, 2017 at 1:42 AM, Lance Kavalsky <
lance.kavalsky at mail.utoronto.ca> wrote:
> Dear All,
>
>
> I have tried the following changes to the system (see latest input file
> below), all of which still converge to the non-magnetic state regardless of
> starting magnetization:
>
>
>
> 1. Breaking the symmetry by treating the two O atoms as different
> species (the unit cell contains 1 Mn and 2 O)
> 2. Introducing the nbnd parameter into &system
> 3. Running the simulation with a finer k-mesh (21x21x7)
> 4. With and without the Hubbard correction
> 5. With and without using noncolin=.true.
> 6. And alternative pseudopotentials (namely Mn.pbe-spn-rrkjus_psl.0.3.1.UPF
> and O.pbe-rrkjus.upf.UPF)
>
> Some papers mention that the ferromagnetism was observed, and others don't
> mention it at all.
>
> I have approached the other members of my group as well to no avail. I
> have been stuck with this for a month and would truly appreciate any
> advice or other suggestions you may have.
>
> &control
> disk_io = 'high',
> calculation ='vc-relax',
> restart_mode = 'from_scratch'
> prefix = 'all',
> outdir = './all',
> Pseudo_dir = './'
> nstep=250,
> /
>
> &system
> lda_plus_u=.true.
> hubbard_U(1)= 3.9
> degauss = 1.00000e-02
> ecutrho = 2.25000e+02
> ecutwfc = 2.50000e+01
> ibrav = 0
> nat = 3
> nspin = 2
> ntyp = 3
> occupations = "smearing"
> smearing = "gaussian"
> starting_magnetization(1) = 1.00000
> starting_magnetization(2) = -0.60000e+00
> starting_magnetization(3) = -0.60000e+00
> nbnd = 19
>
>
>
> /
>
> &electrons
> conv_thr = 1.00000e-06
> electron_maxstep = 200
> mixing_beta = 4.00000e-01
> startingpot = "atomic"
> startingwfc = "atomic+random"
>
> /
>
> &ions
> ion_dynamics = 'bfgs'
> /
>
> &cell
> cell_factor=6.0,
> cell_dofree = '2Dxy',
> /
>
>
> CELL_PARAMETERS {angstrom}
>
> 2.240463696 -0.000000000 0.000000000
> -1.120231848 1.940298414 0.000000000
> 0.000000000 0.000000000 17.431921826
>
> ATOMIC_SPECIES
>
> Mn 54.9380 Mn.pbe-spn-rrkjus_psl.0.3.1.UPF
> O1 15.9994 O.pbe-n-kjpaw_psl.0.1.upf
> O2 15.9994 O.pbe-n-kjpaw_psl.0.1.upf
>
> ATOMIC_POSITIONS {angstrom}
>
> Mn 0.000000000 0.000000000 0.603503436
> O1 1.120233376 0.646765629 -0.789807394
> O2 -0.000000765 1.293533550 1.997300505
>
>
>
> K_POINTS automatic
> 21 21 7 1 1 1
>
>
>
> Thanks so much,
>
> Lance Kavalsky
> MASc student
> Dept. of Materials Science and Engineering
> University of Toronto
>
> ------------------------------
> *From:* pw_forum-bounces at pwscf.org <pw_forum-bounces at pwscf.org> on behalf
> of Lorenzo Paulatto <lorenzo.paulatto at impmc.upmc.fr>
> *Sent:* Thursday, September 7, 2017 3:39:53 AM
> *To:* pw_forum at pwscf.org
> *Subject:* Re: [Pw_forum] Problems Computing Cholesky for VC-Relax of MnO2
>
> On 06/09/17 21:01, Lance Kavalsky wrote:
> > I am no longer getting the error after increasing the energy cutoff of
> > the wavefunctions to 250.0 Ry, decreasing the smearing to 0.01, and
> > resetting the diagonalization back to davidson.
>
>
> You mean of the charge density cutoff?
>
> > I have experimented with varying the starting magnetizations and it
> > consistently converges to a non-magnetic state. However, M. Kan et al.
> > showed that a ferromagnetic state should exist via DFT (J. Phys. Chem.
> > Lett., *2013*, /4/ (20), pp 3382–3386). Is this lack of magnetic states
> > in my investigations more likely a result of not yet discovering a
> > suitable starting magnetization, or could there be another reason such
> > as choice of pseudopotentials?
> >
> I do not know your system, but you may have to start with to different
> species of Mg, in order to break symmetry. This is necessary if one of
> the symmetries of your crystal send Mg1 to Mg2 changing its orientation.
>
> Example:
>
> nat=4, ntyp=3,
> ...
> starting_magnetization(1)=0.5 !Mn1
> starting_magnetization(2)=0.5 !Mn2
> starting_magnetization(3)=-0.5 !Oxygen
> ...
> ATOMIC_SPECIES
> Mn1 54.9380 Mn.pbe-spn-kjpaw_psl.0.3.1.upf
> Mn2 54.9380 Mn.pbe-spn-kjpaw_psl.0.3.1.upf
> O 15.9994 O.pbe-n-kjpaw_psl.0.1.upf
>
> ATOMIC_POSITIONS {angstrom}
> Mn1 1.463698094 2.529784343 0.000006382
> Mn2 2.923484801 0.001355102 1.898036230
> O 0.003938199 1.686984261 0.949009435
> O 1.463753969 0.844151693 2.847056902
>
>
> [resending to list]
>
> --
> Dr. Lorenzo Paulatto
> IdR @ IMPMC -- CNRS & Université Paris 6
> phone: +33 (0)1 442 79822 / skype: paulatz
> www: http://www-int.impmc.upmc.fr/~paulatto/
> mail: 23-24/423 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
--
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170915/d3186df4/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: mno2.in
Type: application/octet-stream
Size: 1483 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170915/d3186df4/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: mno2.out.gz
Type: application/x-gzip
Size: 25447 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20170915/d3186df4/attachment.bin>
More information about the users
mailing list