[Wien] FW: Internal Coordinates minimization for Monoclinic

[Ghosh SUDDHASATTWA]

Dear Prof.Blaha, 
Thanks for the mail. 
I have done the following 
1. Generate the structure file and run a normal SCF with spin orbit
coupling. (Since I am working on an heavy element with 18 atoms per unit
cell)
2. Now my question is 
We can either use option 7 and generate 15 structures and optimize the
structure with minimum energy. 
By modifying the command in optimize.job 
Run_lapw -cc 0.0001 -ec 0.0001 -p -so 

Or, we can simply do min_lapw for the structure file we have generated
initially. 
After running min_lapw, we get the atomic positions with minimum partial
forces, which gets saved in the structure file. 
Now, using the revised (optimized) atomic coordinates, run a SCF. 
By doing so, can we say that we have the structure with minimum total energy
(by doing only min_lapw and not using option 7) 

I hope I am clear enough now. 
Thank you 
Suddhasattwa 

-----Original Message-----
From: wien-bounces at zeus.theochem.tuwien.ac.at
[mailto:wien-bounces at zeus.theochem.tuwien.ac.at] On Behalf Of Peter Blaha
Sent: Monday, June 28, 2010 11:02 AM
To: A Mailing list for WIEN2k users
Subject: Re: [Wien] FW: Internal Coordinates minimization for Monoclinic

Most likely nobody can answer this question, because nobody understands your
question.
At least I did not understand what you are really doing.

Did you run    x optimize with option 7 ?
Did you modify optimize.job or just run it unmodified ?
Did you put min_lapw instead or run_lapw ?
Did you find the structure with lowest total energy ?

> Coming back to my question, doing a 4-D optimization of a monoclinic 
> case by choosing Option 7, can we say with authority that
> 
> 1. Internal coordinates minimization of monoclinic case (with 18 atoms 
> per unit cell) keeping the lattice parameters same would be enough to 
> know the total energy.
> 

> In any case, after lapw_mini, the optimized coordinates are saved in the 
> case.struct, so running the SCf again would give the optimized total 
> energy.

Why would you run again an scf ? You already have one ?


-- 
-----------------------------------------
Peter Blaha
Inst. Materials Chemistry, TU Vienna
Getreidemarkt 9, A-1060 Vienna, Austria
Tel: +43-1-5880115671
Fax: +43-1-5880115698
email: pblaha at theochem.tuwien.ac.at
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