[Pw_forum] Convergence in ZnAlO4

[Lorenzo Paulatto]

      etot_conv_thr = 0.0001
      forc_conv_thr = 0.001

These two values are only used for "relax" calculations, they do no harm 
but they are not needed.

ibrav=0
celldm(1)=1.889726

You can use the keyword "ANGSTROM" after CELL_PARAMETERS instead of this 
hack.


ecutwfc= 60,
ecutrho= 480,

You are using norm-conserving pseudopotentials, no point in setting 
ecutrho any higher than the default value (4*ecutwfc)

occupations='smearing',
smearing='gauss',
degauss=0.000000001,

I do not undertsand this part: if your system is insulator do not use 
smearing (i.e.e occupations="fixed", aka the default). If it is a metal 
use a real smearing (~0.01-0.02) and test convergence wrt the number of 
k-points.


starting_magnetization(1)= 0.6,
starting_magnetization(2)= 0,
starting_magnetization(3)= 1,
nspin= 2,
lda_plus_U=.true.,
Hubbard_U(1)=5,


Does your calculation converge without lda+u?

      wmass = 0.004,

wmass is not used by bfgs


K_POINTS automatic
2  2  2   0 0 0

You will need many many many more k-points woith the very small smearing 
you have used.. Unless your material is insulator.

CELL_PARAMETERS
     15.27919160755835      0.00000000000000      0.00000000000000
      0.00000000000000     15.27919160755835      0.00000000000000
      0.00000000000000      0.00000000000000     15.27919160755835

Use :
CELL_PARAMETER ANGTROM


HTH









On 12/05/15 08:09, Winfred Mulwa wrote:
> Dear all,
> I am running an  scf calculation on the attached input file, but its
> not converging even after changing several parameters.
> Please somebody help me to identify the problem.
> Regards
> Mulwa Winfred.
> D Phil Student, Computational Material Science Group,
> University of the Free State - QwaQwa,
> South Africa.
>
>
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-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
phone: +33 (0)1 44275 084 / skype: paulatz
www:   http://www-int.impmc.upmc.fr/~paulatto/
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