[Pw_forum] problems with vc-relax

Xijun Wang xijunw at gmail.com
Thu Sep 8 17:12:24 CEST 2011 

On Thu, Sep 8, 2011 at 10:26 AM, Elie Moujaes
<elie.moujaes at hotmail.co.uk> wrote:
> Hello Xijun,

Hello Elie,

> I did not send the e-mail twice intentionally. There was a problem with my
> e-mail and it kept giving me an error about problems with Windows hotmai
> hence why it was sent twice without me knowing except now when I opened my
> e-mail so I apologize for that. Also I wont include blank lines in the input
> file either.  Back to my calculations, I have restarted the calculations, it
> went fine at first but then I got the error:
> from scale_h: not enough memory allocated for radial FFT; try restarting
> with a larger cell_factor.

Check the manual for definition of cell_factor. The default value is
1.2, you could try a larger value.

What's your new K_POINTS setting? Since you are relax the system, I
suggest you start from:

     K_POINTS {gamma}

This will far faster. and need far less memory.

> Another simple question: I realized when I restarted everything that the
> positions of the atoms were the initial ones even before starting the
> relaxation process where as the k-points used were the NEW ones. Is that
> normal? or should I have substituted the the C atoms positions by the most
> recent ones then restart again?

Yes, restart again with NEW ATOMIC_POSITIONS and "restart_mode= 'from_scratch' "

Regards,
 - Xijun

> Regards
> Elie
>
>> Date: Wed, 7 Sep 2011 16:20:49 -0400
>> From: xijunw at gmail.com
>> To: pw_forum at pwscf.org
>> Subject: Re: [Pw_forum] problems with vc-relax
>>
>> Hi, Elie,
>>
>> Please do not repeat sending the same message to the mail list. Also,
>> people will be more happy to help you if you keep your mail neat by
>> removing all the unnecessary blank lines in the input file.
>>
>> Regards,
>> Xijun
>>
>> On Wed, Sep 7, 2011 at 3:28 PM, Elie Moujaes <elie.moujaes at hotmail.co.uk>
>> wrote:
>> > Dear all,
>> >
>> >
>> >
>> > I am relaxing a 60 atom supercell (graphene grain boundary) to make the
>> > total force on atoms mainly 0.001 Ry/au. However the vc-relax stopped
>> > after
>> > 4 days of execution and without reaching the desired force threshold.
>> > The
>> > following output was obtained :
>> >
>> >
>> >
>> > 1st relaxation process:
>> >
>> >
>> >
>> > Total force 0.091   Pressure =- 114.1 kbar
>> >
>> >
>> >
>> > 2nd relaxation process:
>> >
>> >
>> >
>> > total force 0.1   Pressure = -55 kbar
>> >
>> >
>> >
>> > (new enthalpy < old enthalpy)
>> >
>> >
>> >
>> > 3rd process:
>> >
>> >
>> >
>> > total force = 0.058   pressure = -11 kbar
>> >
>> >
>> >
>> > Then in the 4th process, calculations stopped. Here are the last few
>> > lines
>> > of the output:
>> >
>> >
>> >
>> > iteration #  2     ecut=    36.75 Ry     beta=0.30
>> >      Davidson diagonalization with overlap
>> >      c_bands:  5 eigenvalues not converged
>> >      c_bands:  1 eigenvalues not converged
>> >      c_bands:  3 eigenvalues not converged
>> >      c_bands:  1 eigenvalues not converged
>> >      c_bands:  4 eigenvalues not converged
>> >      c_bands:  4 eigenvalues not converged
>> >      c_bands:  4 eigenvalues not converged
>> >      c_bands:  4 eigenvalues not converged
>> >      c_bands:  5 eigenvalues not converged
>> >      c_bands:  5 eigenvalues not converged
>> >      c_bands:  2 eigenvalues not converged
>> >      c_bands:  2 eigenvalues not converged
>> >      ethr =  2.90E-04,  avg # of iterations = 17.6
>> >
>> >      negative rho (up, down):  0.132E-01 0.000E+00
>> >
>> >      total cpu time spent up to now is 382283.13 secs
>> >
>> >      total energy              =    -676.77947904 Ry
>> >      Harris-Foulkes estimate   =    -676.82846513 Ry
>> >      estimated scf accuracy    <       0.17363554 Ry
>> >
>> >      iteration #  3     ecut=    36.75 Ry     beta=0.30
>> >      Davidson diagonalization with overlap
>> >      c_bands:  1 eigenvalues not converged
>> >      c_bands:  1 eigenvalues not converged
>> >      c_bands:  2 eigenvalues not converged
>> >      c_bands:  3 eigenvalues not converged
>> >
>> >
>> >
>> > The input of the vc-relax is:
>> >
>> >
>> >
>> > &control
>> >
>> >     prefix='GBphonon',
>> >
>> >     calculation='vc-relax',
>> >
>> >     restart_mode='from_scratch',
>> >
>> >     tstress=.true.,
>> >
>> >     tprnfor=.true,
>> >
>> >     pseudo_dir =
>> > '/exp/home/caiapo/emoujaes/espresso/espresso-4.3/Pseudo/',
>> >
>> >     outdir='/exp/home/caiapo/emoujaes/espresso/Moujaes-Results/',
>> >
>> >
>> >
>> >  /
>> >
>> >  &system
>> >
>> >     ibrav= 0, celldm(1) =1.889725989, nat=60, ntyp= 1, ecutwfc
>> > =36.749309,
>> > occupations='smearing', smearing='mp',degauss=0.01
>> >
>> > /
>> >
>> >  &electrons
>> >
>> >     conv_thr=1.D-6,
>> >
>> >     mixing_beta=0.3D0,
>> >
>> >     diago_david_ndim=2,
>> >
>> >
>> >
>> >  /
>> >
>> >
>> >
>> > &ions
>> >
>> >  ion_dynamics='bfgs'
>> >
>> >
>> >
>> > /
>> >
>> > $cell
>> >
>> > cell_dynamics='bfgs',
>> >
>> >
>> >
>> > /
>> >
>> >
>> >
>> > CELL_PARAMETERS (alat)
>> >
>> >   24.064488464   0.000772242   0.000000000
>> >
>> >    0.000000000   6.503051170   0.000000000
>> >
>> >    0.000000000   0.000000000   8.470514812
>> >
>> >
>> >
>> >
>> >
>> > ATOMIC_SPECIES
>> >
>> >  C  12.0107  C.blyp-mt.UPF
>> >
>> >
>> >
>> > ATOMIC_POSITIONS (angstrom)
>> >
>> > C      -11.330758616  -3.527803203   0.000000000
>> >
>> > C      -10.659793092  -1.160339161   0.000000000
>> >
>> > C      -12.039843315  -7.112619698   0.000000000
>> >
>> > C      -12.041158182  -5.732701936   0.000000000
>> >
>> > C      -10.941089654  -4.881442842   0.000000000
>> >
>> > ......
>> >
>> >
>> >
>> > Please can anyone advice me on this? Shall I start with the new
>> > configuration and start relaxing again?
>> >
>> >
>> >
>> > Regards
>> >
>> >
>> >
>> > Elie Moujaes
>> >
>> > University of Nott
>> >
>> > University Park
>> >
>> > NGT 3RD
>> >
>> >
>> >
>> > _______________________________________________
>> > Pw_forum mailing list
>> > Pw_forum at pwscf.org
>> > http://www.democritos.it/mailman/listinfo/pw_forum
>> >
>> >
>>
>>
>>
>> --
>> Dept. of Chem and Biochem, Concordia University
>> 7141 Sherbrooke Ouest, Montreal, QC, Canada (H4B 1R6)
>> Tel: 514-848-2424-#5835 (Lab) TA office: SP175.23
>> _______________________________________________
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>
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>



-- 
Dept. of Chem and Biochem, Concordia University
7141 Sherbrooke Ouest, Montreal, QC, Canada (H4B 1R6)
Tel: 514-848-2424-#5835 (Lab) TA office: SP175.23

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