Hi,
You are right. Tests should be done. I was suggesting "start" from
gamma k-points to make a quick relaxation. After this, relaxation with
larger k-points could be followed if necessary.
Regards,
Xijun
On Thu, Sep 8, 2011 at 7:35 PM, WF <windbellklbh at gmail.com> wrote:
> Is it good enough to relax an arbitrary system with only gamma k-points? I
> thought it is necessary to do some test with k-points as this effect change
> from system to system. In my experience, more k-points is necessary for a
> metal-like system, i.e. graphene.
>
> Best regards,
>
> Wu, F
>
>> Date: Thu, 8 Sep 2011 11:12:24 -0400
>> From: xijunw at gmail.com
>> To: pw_forum at pwscf.org
>> Subject: Re: [Pw_forum] problems with vc-relax
>>
>> 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
>> >> _______________________________________________
>> >> Pw_forum mailing list
>> >> Pw_forum at pwscf.org
>> >> http://www.democritos.it/mailman/listinfo/pw_forum
>> >
>> > _______________________________________________
>> > 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
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>
> -----------------------------------------------------------
> Wu, F
> College of Chemistry and Molecular Engineering, Peking University
> ----------------------------------------------------------
>
> _______________________________________________
> 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
