[Wien] Charge Convergence is not achieved

[Peter Blaha]

For just 3 atoms/cell (and metallid ??) 1000 or 5000 k are still not much.
Better k-mesh should improve convergence.

And sometimes you cannot reach (easily) arbitrary convergence. What about E-tot, ... ?


Am 06.07.2011 07:48, schrieb Shamik Chakrabarti:
> Dear wien2k users,
>
> We have done volume optimization of a structure having space group no. 225 (Fm3m) and 3 inequivalent atoms per unit cell. We have taken the least energy lattice parameters for
> spin polarized SCF calculations. However, the last calculation (spin polarized SCF) has not been converging at all. We have set the convergence criteria of  charge to 0.0001and it
> reached up to 0.006. After that its is fluctuating sinusoidally at this value (even at around 400th iteration). We have also tried using the fallowing steps, such as
>
> 1. increasing the RmaxKmax value from 7 to 9
>
> 2. changing mixer values ranging from 0.01 to 0.3 (using MSEC mixing scheme...wien2k 10)
>
> 3. increasing the K-points from 1000 to 5000
>
> but unfortunately we haven't got the desired convergence yet. Therefore, it is very helpful for us to have a suggestion for this problem.
>
> --
> Shamik Chakrabarti
> Research Scholar
> Dept. of Physics & Meteorology
> Material Processing & Solid State Ionics Lab
> IIT Kharagpur
> Kharagpur 721302
> INDIA
>
>
>
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-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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