[Pw_forum] problems with vc-relax

[Xijun Wang]

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
>
>
>
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>



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