[Wien] Lattice parameters in the SCF cycle

tran at theochem.tuwien.ac.at tran at theochem.tuwien.ac.at
Wed Sep 6 23:18:29 CEST 2017


Hi,

When you execute run(sp)_lapw, the lattice parameters don't change.
To optimize the lattice parameters you need first to execute "x optimize",
which generates a series of struct files. Then execute optimize.job which
will run SCF for each of one the struct files.

Look at the 2nd exercise here:
http://susi.theochem.tuwien.ac.at/onlineworkshop/Exercises-all.pdf

FT

On Wed, 6 Sep 2017, Indika udaya wrote:

> Dear WiEn2k experts
> 
> I recently started WIEn2k. I have a basic question on optimization of the structure which I am confused on.
> 
> I need to get the lattice parameters with and without adding Hubbard U and spin orbital coupling to my structure. For that I started with the experimental
> values and performed the SCF cycle. It converged with cc 0.0001 and ec 0.00001. But I noticed the initial lattice parameters I started remains the same until
> the last iteration of the scf cycle ( at the 53rd iteration).
> 
> Then I added hubbard U (5eV) to the calculation and finished the scf with same convergence criteria. Next finished scf with U+SO.
> But in all the cycles lattice parameter did not change.
> 
> I am not sure whether this observation is correct with WIEN2k *( or i am missing something during the calculation??)
> 
> If so, how do I check the changes of lattice parameters with Hubbard-U and SO?? Do I need to do volume optimization for each of the steps (namely for scf, SCF+U
> and for SCF+U+SO seperately) and use the lattice parameters at minimum energy position ?
> 
> Thank you for your time and I am waiting for a quick responce.
> 
> Indika
> PhD Candidate
> 
> 
> 
>


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