[Wien] A basic question regarding structure optimization

[Peter Blaha]

You CAN DO AND probably SHOULD ALWAYS DO a simultaneously optimization 
of external (lattice parameters) and internal (atomic positions) degrees 
of freedom with wien2k.
Just use MSR1a  in the   run_lapw  step in volume optimization or 
replace run_lapw by min_lapw in any script.

The "error" could be small (or almost zero), or could be very large 
(giving you meaningless results). This depends on your specific case.


On 09/23/2013 06:27 AM, shamik chakrabarti wrote:
> Sir,
>
>       I have a basic question regarding the method of structure
> optimization in wien2k.
>
> If we optimize it in two  successive steps (i) first optimize volume and
> lattice parameters and then (ii) for structure having optimized volume
> and lattice parameters further optimization of structural coordinates......
>
> how much different (or how much erroneous !!) will be the final optimize
> structure in comparison to that obtained by simultaneous variation of
> lattice parameters and structural coordinates as can be done in PAW code
> VASP.
>
> Any response in this regards will be very helpful for us. Thanks in advance.
>
> with regards,
>
> --
> Shamik Chakrabarti
> Senior Research Fellow
> 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
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