[Pw_forum] phonon calculation crashes

Stefano Baroni baroni at sissa.it
Fri Jan 30 11:16:17 CET 2009


I am a bit confused. I thought that the maximum dimension of any irrep  
of any point group compatible with lattice translations was 3. The  
number 4 may arise form complications with non-symmorphic groups (such  
as at the X point of the diamond structure), which I used to me kind  
of familiar with, but that I do not remember any longer. I am  
surprised that the need of any irrep larger that 4 may ever arise, but  
this surprise may well be due to the rustiness of my knowledge in  
group theory - Cheers - Stefano B

On Jan 30, 2009, at 10:45 AM, Eyvaz Isaev wrote:

> Dear Merlin,
>
> This one is also a famous message, though I did heard about it since  
> long time.
>
> Well, this means you have more dimension for irreducible  
> reperesentations that allowed by default, max_irr_dim=4. See  
> phcom.f90 for sure.
>
> So, you can just increase this parameter (up to a reasonable value  
> 6, 8, ... ) in phcom.f90 and recompile ph.x.
> Then it should work.
>
> Bests,
> Eyvaz.
>
> -------------------------------------------------------------------
> Prof. Eyvaz Isaev,
> Theoretical Physics Department, Moscow State Institute of Steel &  
> Alloys, Russia,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping  
> University, Sweden
> Condensed Matter Theory Group, Uppsala University, Sweden
> Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
> --- On Fri, 1/30/09, merlin meheut <meheut at impmc.jussieu.fr> wrote:
>
>> From: merlin meheut <meheut at impmc.jussieu.fr>
>> Subject: [Pw_forum] phonon calculation crashes
>> To: "PWSCF Forum" <pw_forum at pwscf.org>
>> Date: Friday, January 30, 2009, 6:19 AM
>> Dear all,
>>
>> I have had a strange crash on a phonon calculation, with
>> version
>> 3.2.3: I have calculated the dynamical matrix of the
>> structure at
>> gamma, at q-point (0;0.5;-0.5), both without problems, but
>> I cannot
>> calculate the (0;0;-1) q-point without having this error:
>>
>>
>> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
>> %%%%%%%%%%
>>      from set_irr : error #         2
>>      npert > max_irr_dim
>>
>> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
>> %%%%%%%%%%
>>
>> I don't know what this means. The structure I am
>> calculating is very
>> big (80 atoms), so maybe it is related, I don't know.
>>
>> Follows the input files:
>>
>> --------------------------- scf input file:
>>   pyrope    Pavese 1995 (30K) cubique centre
>>  &control
>>        calculation = 'scf',
>>       restart_mode = 'from_scratch' ,
>>             prefix = 'PYROPE',
>>            disk_io = 'default' ,
>>     pseudo_dir     = './',
>>     outdir         = '/tmp/',
>>     tprnfor        = .true.,
>>     tstress        = .true.,
>> /&end
>> &system
>>     ibrav =3, celldm(1)=21.9096,
>>     nat =80, ntyp = 4, ecutwfc = 80.0
>> /&end
>>  &electrons
>>    electron_maxstep = 60,
>>           conv_thr = 1.d-7 ,
>>        mixing_mode = 'plain',
>>        startingwfc = 'atomic',
>>        mixing_beta = 0.4,
>>    diagonalization = 'david_overlap',
>> /&end
>> ATOMIC_SPECIES
>>   Al   26.9815   Al.pbe2
>>   Mg   23.9850   Mgpbe1_mt.ncpp
>>   Si   27.9769   Si.pbe2
>>   O    15.9949   O.pbe
>> ATOMIC_POSITIONS crystal
>> Si     0.62500000   0.62500000   0.25000000
>> (...)
>>
>> K_POINTS {crystal}
>> 1
>>  0.25 0.25 0.25 1
>> -------------------------------------------------------------------
>>
>> ------------------------------------------nscf input file:
>>
>>  pyrope    Pavese 1995 (30K) cubique centre
>>  &control
>>        calculation = 'phonon',
>>       restart_mode = 'from_scratch' ,
>>             prefix = 'PYROPE',
>>            disk_io = 'default' ,
>>     pseudo_dir     = './',
>>     outdir         = '/tmp/',
>>     tprnfor        = .true.,
>>     tstress        = .true.,
>> /&end
>> &system
>>     ibrav =3, celldm(1)=21.9096,
>>     nat =80, ntyp = 4, ecutwfc = 80.0
>> /&end
>>  &electrons
>>    electron_maxstep = 60,
>>           conv_thr = 1.d-7 ,
>>        mixing_mode = 'plain',
>>        startingwfc = 'atomic',
>>        mixing_beta = 0.4,
>>    diagonalization = 'david_overlap',
>> /&end
>> &phonon
>> xqq(1)= 0.0000000, xqq(2)= 0.0000000, xqq(3)= -1.0000000
>> /&end
>> ATOMIC_SPECIES
>>   Al   26.9815   Al.pbe2
>>   Mg   23.9850   Mgpbe1_mt.ncpp
>>   Si   27.9769   Si.pbe2
>>   O    15.9949   O.pbe
>> ATOMIC_POSITIONS crystal
>> Si     0.62500000   0.62500000   0.25000000
>> Si     0.87500000   0.87500000   0.75000000
>> (....)
>>
>> K_POINTS {crystal}
>> 1
>>  0.25 0.25 0.25 1
>> -------------------------------------------------------------------
>>
>> -----------------------ph input file:
>>
>> Pyrope m2
>>  &inputph
>>   amass(1)=26.9815,
>>   amass(2)=23.9850,
>>   amass(3)=27.9769,
>>   amass(4)=15.9949,
>>   alpha_mix(1) = 0.7,
>>    tr2_ph =  1.0D-16,
>>    prefix='PYROPE',
>>    fildyn='mat.strelD.bald.m3',
>>    epsil =.false.,
>>    trans =.true.,
>>    zue = .false.,
>>    outdir='/tmp/'
>> /&end
>> 0.0 0.0 -1.0000000
>> -----------------------------------------------------
>>
>>
>> Has anyone an idea on the importance or the origin of this
>> error?
>>
>> Thanks for any hints,
>>
>> Best regards,
>>
>> Merlin Meheut
>>
>> ESS department at UCLA
>>
>>
>>
>>
>>
>>
>>
>>
>> --
>> Merlin Méheut
>> professional adress:
>> 595 Charles Young Drive East
>> 3806 Geology Building
>> Los Angeles, California 90095-1597
>> United States of America
>> tel: 310 825 7934
>> cell phone: 310 893 4253
>>
>> ----------------------------------------------------------------
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>> Program.
>>
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>
>
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---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center -  
Trieste
http://www.sissa.it/~baroni / [+39] 040 3787 406 (tel) -528 (fax) /  
stefanobaroni (skype)

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