[Pw_forum] SCF correction problem in relaxation

[Jhon W. González]

Hi,

I'm trying to relax a cell to calculate transport properties of zigzag
graphene nanoribbon, but there is something wrong, because for all
parameters, always get the same final result

 SCF correction compared to forces is too large, reduce conv_thr

This message appears for all conv_thr parameters (From 1.0D-6 to 1.0D-1)

Thanks a lot,

##########################
 &CONTROL
...  etot_conv_thr = 1.0D-4 ,
     forc_conv_thr = 1.0D-3 ,
 /
 &SYSTEM
...  occupations = 'smearing' ,
     degauss = 0.01 ,
     smearing = 'fermi-dirac' ,
 /
 &ELECTRONS
     electron_maxstep = 100,
     conv_thr = 1.0D-5 ,
 /
 &IONS
 /
##############################

Produces an output like:

    Total force =     0.001237     Total SCF correction =     0.000289
     SCF correction compared to forces is too large, reduce conv_thr
     bfgs converged in  11 scf cycles and   8 bfgs steps
     End of BFGS Geometry Optimization


############################
&ELECTRONS
 diagonalization = 'cg',
  mixing_mode = 'plain',
  mixing_beta = 0.7,
  conv_thr    = 1.D-6,
  mixing_beta = 0.3D0,
/
&IONS
  ion_dynamics='bfgs'
  bfgs_ndim  = 1,
  pot_extrapolation = "second_order",
  wfc_extrapolation = "second_order",
/
#############################
Also produce the same warning

SCF correction compared to forces is too large, reduce conv_thr


Jhon W. González

Universidad Técnica Federico Santa María
Fono (56) (32) 2654623 Fax  (56) (32) 2797656
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CHILE

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