[Wien] Slow convergence of charge

[Lyudmila Dobysheva]

On 16.12.2014 08:56, Shafqat Hussain Shah wrote:
> the atomic positions of the system using MSR1a, it is, unexpectedly,
> very slow (around 300 iterations) in charge convergence.
> runsp_lapw -p -i 999 -ec 0.0001 -cc 0.001 -fc 0.50
> all
> the calculations with experimental parameters and Optimizer generated
> structures for option 1, 3 and 4 converge nicely (around 80 iterations
> with the above mentioned command).

As far as I remember a standard procedure for MSR1a should start from a 
partly converged solution, that is, first, without MSR1a:
run_lapw -p -cc 0.1 -ec 0.25 -fc 20 -i 60
save (to clean the directory)
then change the case.inm to MSR1a
and run_lapw with good criteria for convergence -cc 0.0015

I see that in the first iteration you have
:DIS=  ( 1.5480230 for atom    3 spin 2)      2.9889210
that is rather large. The calculated forces are not correct yet, your 
system goes far from reality. Maybe for experimental lattice you had 
started from a converged solution, so forces had been correct in the 
first iteration already, and finding the equilibrium was short.

Best regards
   Lyudmila Dobysheva
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