[Pw_forum] Convergence NOT achieved for Sr2MnMoO6 using PAW pp
Shuai
zhao-shuai at edu.life.kyutech.ac.jp
Sat Oct 10 05:00:40 CEST 2015
Dear Stefano and Pang,
Thank you very much for your advices.
I reduced to 10 atoms, then it converged well. But when I enlarged to 40
atoms, it cannot converge with the same parameters of 10 atoms.
I then made a little change about the lattice parameters:
Sr (0, 0, 0) --> Sr (0.25, 0.25, 0.25)
Mn (0.25, 0.25, 0.25) --> Mn (0, 0, 0)
Mo (0.75, 0.25, 0.25) --> Mo (0.5, 0, 0)
O (0.25, 0.25, 0) --> O (0.25, 0, 0)
and it can also converged well. What confused me is the difference
between two lattice parameters is only a displacement, why causing the
different convergence results?
Best regards,
Shuai Zhao
On 10/09/2015 04:43 PM, stefano de gironcoli wrote:
> I would give a shot to local-TF, mixing-beta not too small (~ 0.3).
>
> is it a metal ? does increasing degauss help ?
> is this an instability related to the occupation of the U-projectors ?
> does it converge if you if you remove U ?
> does the fcc cell with 10 atoms converge ?
>
> stefano
>
> On 09/10/2015 09:03, 庞瑞(PANG Rui) wrote:
>> Dear Zhao
>> The most efficient way is reducing the mixing_beta, you may try 0.1
>> -0.01 or even smaller if you can afford the CPU time. Is 50 enough
>> for O? You may check it, the smallest value usually is given in the
>> PP file. A personal experience is that do not use semi-core PP. I do
>> not understand the reason but I seldom get convergence when using
>> semi-core PPs in periodical cases with PWSCF.
>> Good luck
>>
>>
>>
>>
>> ------------------
>>
>>
>> 庞瑞 (PANG Rui)
>>
>> South University of Science and Technology of China/Department of Physics
>>
>> No.1088,Xueyuan Road, Shenzhen,Guangdong
>>
>> ------------------ Original ------------------
>> *From: * "Shuai"<zhao-shuai at edu.life.kyutech.ac.jp>;
>> *Date: * Fri, Oct 9, 2015 12:00 PM
>> *To: * "PWSCF Forum"<pw_forum at pwscf.org>;
>> *Subject: * [Pw_forum] Convergence NOT achieved for Sr2MnMoO6 using
>> PAW pp
>> Dear User:
>>
>> I am doing the SCF calculation of Sr2MnMoO6 using PAW Potentials but it
>> cannot converged.
>>
>> I checked different Ecut (30Ry, 40Ry or 50Ry), mixing mode (TF or
>> plain), diagonalization (david or cg) and mixing_beta (0.3, 0.7), but it
>> always not converged.
>>
>> The SCF input is:
>>
>> &control
>> calculation = 'scf'
>> prefix = 'Sr2MnMoO6'
>> restart_mode = 'from_scratch'
>> pseudo_dir = '/'
>> outdir = '/'
>> /
>> &system
>> ibrav = 1
>> celldm(1) = 15.27295
>> nat = 40
>> ntyp = 4
>> ecutwfc = 50
>> ecutrho = 600
>> occupations = 'smearing'
>> smearing = 'mp'
>> degauss = 0.01
>> lda_plus_u = .true.
>> Hubbard_U(2) = 4.0
>> /
>> &electrons
>> conv_thr = 1e-8
>> mixing_mode = 'TF'
>> mixing_beta = 0.7
>> diagonalization = 'david'
>> /
>> ATOMIC_SPECIES
>> Sr 87.620 Sr.pbe-spn-kjpaw_psl.1.0.0.UPF
>> Mn 54.938 Mn.pbe-spn-kjpaw_psl.1.0.0.UPF
>> Mo 95.960 Mo.pbe-spn-kjpaw_psl.1.0.0.UPF
>> O 15.999 O.pbe-n-kjpaw_psl.1.0.0.UPF
>> ATOMIC_POSITIONS (crystal)
>> Sr 0.0000 0.0000 0.0000
>> Sr 0.5000 0.0000 0.0000
>> Sr 0.0000 0.5000 0.0000
>> Sr 0.5000 0.5000 0.0000
>> Sr 0.0000 0.0000 0.5000
>> Sr 0.5000 0.0000 0.5000
>> Sr 0.0000 0.5000 0.5000
>> Sr 0.5000 0.5000 0.5000
>> Mn 0.2500 0.2500 0.2500
>> Mo 0.7500 0.2500 0.2500
>> Mo 0.2500 0.7500 0.2500
>> Mn 0.7500 0.7500 0.2500
>> Mo 0.2500 0.2500 0.7500
>> Mn 0.7500 0.2500 0.7500
>> Mn 0.2500 0.7500 0.7500
>> Mo 0.7500 0.7500 0.7500
>> O 0.2500 -0.0140 0.2500
>> O -0.0140 0.2500 0.2500
>> O 0.2500 0.2500 -0.0140
>> O 0.7500 0.0140 0.2500
>> O 0.5140 0.2500 0.2500
>> O 0.7500 0.2500 0.0140
>> O 0.2500 0.5140 0.2500
>> O 0.0140 0.7500 0.2500
>> O 0.2500 0.7500 0.0140
>> O 0.7500 0.4860 0.2500
>> O 0.4860 0.7500 0.2500
>> O 0.7500 0.7500 -0.0140
>> O 0.2500 0.0140 0.7500
>> O 0.0140 0.2500 0.7500
>> O 0.2500 0.2500 0.5140
>> O 0.7500 -0.0140 0.7500
>> O 0.4860 0.2500 0.7500
>> O 0.7500 0.2500 0.4860
>> O 0.2500 0.4860 0.7500
>> O -0.0140 0.7500 0.7500
>> O 0.2500 0.7500 0.4860
>> O 0.7500 0.5140 0.7500
>> O 0.5140 0.7500 0.7500
>> O 0.7500 0.7500 0.5140
>> K_POINTS (automatic)
>> 4 4 4 1 1 1
>>
>> Thanks in advance for your suggestions.
>>
>> Best regards,
>>
>> Shuai Zhao
>>
>> --
>> PhD candidate
>> Graduate School of Life Science and Systems Engineering
>> Kyushu Institute of Technology, Japan
>>
>> _______________________________________________
>> 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
>
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
--
PhD candidate
Graduate School of Life Science and Systems Engineering
Kyushu Institute of Technology, Japan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20151010/6ce9d0e1/attachment.html>
More information about the users
mailing list