[Pw_forum] vc-relax problem

[David Foster]

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.
==========================

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