[Wien] constrain some atoms to minimize the forces

[Laurence Marks]

Your question is based upon a common misunderstanding of minimizing forces.
You are thinking that the time to optimize depends upon the number of
positions (3*Number of Pt atoms that move) which is wrong. With PORT it
scales as the number of clusters of phonon frequencies and weakly with the
width of the clusters; with MSR1a it scales as the number of clusters of
eigenvalues of the joint electron-phonon problem and their width.

You will gain far more by generating a proper symmetric model with P-3m1
(maybe P-31m) symmetry rather than what you appear to have, a P1 structure.
This will reduce the number of uniques phonon etc modes by something like
6-12, and will be much faster and converge better.

---
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
http://www.numis.northwestern.edu
Corrosion in 4D http://MURI4D.numis.northwestern.edu
Partner of the CFW 100% gender equity project, www.cfw.org/100-percent
Co-Editor, Acta Cryst A

On Jul 14, 2016 06:25, "Saleem Ayaz" <saleemayaz_hu at yahoo.com> wrote:

Dear users
I want to minimize the forces for Pt111 surface. I want to restrict the
structure by minimizing the forces for first two layers and keeping the
other layers bulk-like. Please some one can help me how to change case.inM
file. Should I make some numbers equal to zero?
Looking forward

regards
Saleem

PORT 2.00 0.35      # PORT/NEWT;  tolf, Initial Trust Radius
1.0 1.0 1.0 1.0   #Atom    1 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    2 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    3 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    4 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    5 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    6 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    7 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    8 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom    9 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   10 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   11 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   12 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   13 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   14 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   15 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   16 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   17 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   18 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   19 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   20 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   21 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   22 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   23 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   24 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   25 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   26 Generated by pairhess
1.0 1.0 1.0 1.0   #Atom   27 Generated by pairhess
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