[Pw_forum] vc-relax problem

David Foster davidfoster751 at yahoo.com
Wed Mar 16 22:06:02 CET 2016


Thanks Lorenzo, it is not logical (especially, for a long time job) to evaluate this parameter by try and error. Is it a way to estimate it before the run?
I think it is much better to use relax command + changing lattice size instead of vc-relax. How do you think?

Regards
 
 David Foster
 
 Ph.D. Student of Chemistry

--------------------------------------------
On Wed, 3/16/16, Lorenzo Paulatto <lorenzo.paulatto at impmc.upmc.fr> wrote:

 Subject: Re: [Pw_forum] vc-relax problem
 To: "PWSCF Forum" <pw_forum at pwscf.org>, "David Foster" <davidfoster751 at yahoo.com>
 Date: Wednesday, March 16, 2016, 11:58 PM
 
 
 
 On 16 Mar 2016 9:19 p.m., "David Foster" <davidfoster751 at yahoo.com>
 wrote:
 
 >
 
 > Dear Users and Developers,
 
 > I have constructed supercell of N-doped Graphene and
 then somewhat enlarged its lattice parameres a and b (and of
 course a is equal to b). However, it finished with following
 issue:
 
 >
 
 > ======================
 
 > Error in routine scale_h (1):
 
 >      Not enough space allocated for radial FFT: try
 restarting with a larger cell_factor.
 
 > ==========================
 Just do that.. Cell_factor is an input
 parameter. However I'm not sure that vc relax, or the
 stress calculation is reliable and we'll defined if your
 cell is charged (how do you dope it?)
 HTH, 
 
 Lorenzo
 
 
 >
 
 > This is my input:
 
 >
 
 >
 
 >
 ==========================================================
 
 > &CONTROL
 
 >                        title =
 'graph55'
 
 >                  calculation =
 'vc-relax'
 
 >                 restart_mode =
 'from_scratch'
 
 >                       outdir =
 './graph55',
 
 >                   pseudo_dir = './'
 
 >                       prefix =
 'graph55'
 
 >                      disk_io =
 'default'
 
 >                    verbosity =
 'default'
 
 >                    etot_conv_thr=1.0D-7
 
 >                    forc_conv_thr=1.0D-4
 
 >                    nstep=1000
 
 > /
 
 > &SYSTEM
 
 >                        ibrav = 4
 
 >                        nat = 50
 
 >                      
  celldm(1)=23.489294
 
 >                      
  celldm(3)=1.206758
 
 >                        ntyp = 2
 
 >                        ecutwfc = 50
 
 >                        ecutrho = 400
 
 >                      
  starting_magnetization(1)=0.0
 
 >                      
  starting_magnetization(2)=0.5
 
 >                        nspin=2
 
 >                      
  occupations='smearing'
 
 >                        degauss=0.001
 
 >                      
  smearing='mv'
 
 >                        nbnd=480
 
 >
 
 > /
 
 > &ELECTRONS
 
 >             electron_maxstep = 1000
 
 >                     conv_thr = 1.0D-8
 
 >                  mixing_mode =
 'plain'
 
 >                  mixing_beta = 0.6
 
 >                  mixing_ndim = 15
 
 >              diagonalization =
 'david'
 
 > /
 
 > &IONS
 
 >             ion_dynamics = 'bfgs'
 
 > /
 
 > &CELL
 
 >             cell_dynamics = 'bfgs'
 
 > /
 
 > ATOMIC_SPECIES
 
 >    C   12.0107 
  C.revpbe-n-kjpaw_psl.1.0.0.UPF
 
 >    N   14.0067 
  N.revpbe-n-kjpaw_psl.1.0.0.UPF
 
 > ATOMIC_POSITIONS crystal
 
 >   C  -0.0035332843482924   0.1851606795737290 
  0.0007869079000000
 
 >   C   0.0634271391536306   0.1185672123378320 
  0.0007985082000000
 
 >   C   0.1972118104100160   0.1853479022359610 
  0.0008411762000000
 
 >   C   0.2640546796835970   0.1183863082006620 
  0.0009013451000000
 
 >   C   0.3969086810996360   0.1847817800592880 
  0.0009532216000000
 
 >   C   0.5956703644545790   0.1847899234385230 
  0.0009535323000000
 
 >   C   0.6620952820613830   0.1183858687084460 
  0.0008990575000000
 
 >   C   0.7959137330003590   0.1853435760570340 
  0.0008381939000000
 
 >   C   0.8629092298955131   0.1185585471602930 
  0.0007960819000000
 
 >   C  -0.0035150546870443   0.3851557202317041 
  0.0007940836000000
 
 >   C   0.0631838589318034   0.3186049498829150 
  0.0007792434000000
 
 >   C   0.1964457156160120   0.3851562851338740 
  0.0007933639000000
 
 >   C   0.2632838872396650   0.3184362406096610 
  0.0008320941000000
 
 >   C   0.3962746887700520   0.3844348851829029 
  0.0008478821000000
 
 >   C   0.4633829529931270   0.3177351000329150 
  0.0009047888000000
 
 >   C   0.5966074788692490   0.3854315630482320 
  0.0008457238000000
 
 >   C   0.6621190897524240   0.3177365375096750 
  0.0009084184000000
 
 >   C   0.7959398316409772   0.3844368174251561 
  0.0008509560000000
 
 >   C   0.8629199294456980   0.3184362167353211 
  0.0008339366000000
 
 >   C  -0.0035338673838872   0.5851396932290081 
  0.0008066546000000
 
 >   C   0.0631828018860480   0.5185244995082190 
  0.0007939395000000
 
 >   C   0.1964417765107390   0.5851050828686231 
  0.0008011519000000
 
 >   C   0.2631050290407810   0.5185229929166390 
  0.0007907967000000
 
 >   C   0.3964498615623250   0.5851408711536121 
  0.0008013268000000
 
 >   C   0.4631600273382970   0.5183053159798940 
  0.0008129827000000
 
 >   C   0.5962440563130300   0.5850417316123839 
  0.0007996048000000
 
 >   C   0.6630008615229410   0.5182306760627760 
  0.0008043849000000
 
 >   C   0.7965775260836450   0.5850387078390509 
  0.0008039151000000
 
 >   C   0.8629155401533460   0.5183093186011401 
  0.0008193526000000
 
 >   C  -0.0033916823133423   0.7850662361778210 
  0.0007997306000000
 
 >   C   0.0634101234250425   0.7187980286682670 
  0.0008217964000000
 
 >   C   0.1971891482432570   0.7856552562612531 
  0.0008570577000000
 
 >   C   0.2632663498936130   0.7187701364726640 
  0.0008505618000000
 
 >   C   0.3962428547644810   0.7856593672924379 
  0.0008523345000000
 
 >   C   0.4631548736327530   0.7187974024545640 
  0.0008142026000000
 
 >   C   0.5962365218114650   0.7850664959157701 
  0.0007908983000000
 
 >   C   0.6630323786577090   0.7185060088037540 
  0.0007742824000000
 
 >   C   0.7964705953600870   0.7851503463114868 
  0.0007759114000000
 
 >   C   0.8632460667289600   0.7185087677298430 
  0.0007795964000000
 
 >   C  -0.0034053781659958   0.9853764016728360 
  0.0007854744000000
 
 >   C   0.0635533974119052   0.9187469611954919 
  0.0008003277000000
 
 >   C   0.1962427491566600   0.9850440103004491 
  0.0008482846000000
 
 >   C   0.2640035494748090   0.9195524304057730 
  0.0009266913000000
 
 >   C   0.3968289999039731   0.9858822472737551 
  0.0009841481000000
 
 >   C   0.4633106954544801   0.9195552131133050 
  0.0009214067000000
 
 >   C   0.5965808827582050   0.9850424408181000 
  0.0008394477000000
 
 >   C   0.6629579286767470   0.9187453484234860 
  0.0007918820000000
 
 >   C   0.7965538253125150   0.9853722213410399 
  0.0007802641000000
 
 >   C   0.8632342863818040   0.9186931763034320 
  0.0007636222000000
 
 >   N   0.4631246241068560   0.1185000696135500 
  0.0009700199000000
 
 > K_POINTS automatic
 
 > 4 4 1 0 0 0
 
 >
 
 >
 =====================================================
 
 >
 
 > It seems it is better not to use vc-relax, and instead
 use relax+changing volume by hand :-)
 
 > Anybody can help to solve this problem?
 
 >
 
 > Regards
 
 >
 
 >  David Foster
 
 >
 
 >  Ph.D. Student of Chemistry
 
 > _______________________________________________
 
 > Pw_forum mailing list
 
 > Pw_forum at pwscf.org
 
 > http://pwscf.org/mailman/listinfo/pw_forum
 
 




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