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[pascal boulet <pascal.boulet@univ-provence.fr>]

Dear Rye,

At first sight, since the cutoff energy is low (13 Ha), I guess you are using PAW or ultrasoft pseudopotentials. If it is not the case (i.e. norm-conserving psp: MT or Goedeker) I suggest to increase ecut up to about 70 Ry (for MT) or 90 Ry (for goedeker).

Otherwise, a wrong structure can lead to difficult convergence of the density.
What system are you interested in? Ir4H2?
If yes, then you have to answer the question whether it is metallic or not, in which case you may have to/should use tools for broadening the electrons near the Fermi level (see occopt in the manual for that).

Once you have solved the problem of convergence, I also advise you to decrease the criteria for the convergence of the energy toldfe down to at least 1e-7 (with no units given) and use k-points since the cell is rather small.

Hope this help a bit,
Pascal

Rye Terrell a écrit :

ef7b88470910112256x65197dbfn807ded51cd60ac04@mail.gmail.com" type="cite">Hi everyone,

I submit the following input file to abinit:

ecut 368 eV
nstep 512
toldfe 1.0d-3 eV

acell 3.843479 3.843479 3.843479 angstroms
rprim 1 0 0  0 1 0  0 0 1
ntypat 2
znucl   1 77
natom 6
typat  2 2 2 2 1 1
xangst  0.192173926625 0.192173926625 0.192173926625
        0.192173926625   2.1139131929   2.1139131929
          2.1139131929 0.192173926625   2.1139131929
          2.1139131929   2.1139131929 0.192173926625
        0.330133922984  1.97581998601 0.330339691348
         3.05034388421  3.09920533477  3.05037017781

For some reason, my calculation does not converge very well:

...
 ETOT509  -99.967600677647     7.946E-03 2.238E-05 1.743E+01 1.348E-02 5.832E-02
 ETOT510  -99.971348913873    -3.748E-03 3.132E-05 1.371E+01 6.212E-03 6.023E-02
 ETOT511  -99.970856919498     4.920E-04 9.470E-06 1.497E+01 1.438E-02 5.768E-02
 ETOT512  -99.962207567125     8.649E-03 9.493E-05 2.549E+01 9.176E-02 5.033E-02

 Cartesian components of stress tensor (hartree/bohr^3)
  sigma(1 1)= -1.48092765E-03  sigma(3 2)=  4.93782918E-05
  sigma(2 2)= -1.19629690E-03  sigma(3 1)= -9.22122242E-06
  sigma(3 3)= -6.46521337E-04  sigma(2 1)= -7.09301595E-04

 scprqt:  WARNING -
  nstep=  512 was not enough SCF cycles to converge;
  maximum energy difference=  8.649E-03 exceeds toldfe=  3.675E-05

Can anyone tell me where I need to start looking to correct this?

Thanks for any advice!

Cheers,
Rye

-- 
Dr. pascal Boulet, computational chemist
Laboratoire Chimie Provence, UMR 6264
University of Aix-Marseille I 
Avenue Escadrille Normandie-Niemen
13397 Marseille Cedex 20
France
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