[Wien] Query regarding structure optimization
Gavin Abo
gsabo at crimson.ua.edu
Tue Jun 23 07:06:48 CEST 2020
The WIEN2k 19.1 usersguide [1] on page 67 under section 5.1.4 has:
-dm -> calculate the density matrix (when -so is set, but -orb
is not)
That seems to indicate that the -dm needs -so to work (e.g., runsp_lapw
-dm -so). If you use "runsp_lapw -dm -orb", the program will probably
ignore the -dm switch and run fine. However, if you care about proper
usage it would seem to be "runsp -orb" without the -dm based on that
description in the usersguide.
On 21 June 2020, it looks like it was advised in the post [2] to use
-min [3,4]. Based on that, you might want to reconsider your use of the
min_lapw optimize.job line (min -I -j "run_lapw -I -fc 1.0 -i 40 ") in
your email below.
It looks like it would be fine to use for -orb [5,6] and spin
polarization, in optimize.job for simultaneous optimization of lattice
parameters and atomic positions [7], the following line:
runsp_lapw -orb -ec 0.0001 -cc 0.01 -fc 1 -min
However, if you encounter convergence problems, you might have to take
the advice [8,9] to try a crude convergence followed by a more refined
convergence such as:
runsp_lapw -orb -ec 0.1 -cc 0.01 -fc 4
save_lapw -d ${i}PreMin
runsp_lapw -orb -ec 0.0001 -cc 0.001 -fc 1 -min
[1] http://susi.theochem.tuwien.ac.at/reg_user/textbooks/usersguide.pdf
[2]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20232.html
[3]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13712.html
[4]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18055.html
[5]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18844.html
[6]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19278.html
[7]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18071.html
[8]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17228.html
[9]
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18069.html
On 6/22/2020 7:40 AM, shamik chakrabarti wrote:
> Dear Wien2k users,
> Whether this is the correct approach for
> editing optimize.job to run simultaneous force optimization with *-dm
> -orb and spin polarization* *on*;
>
> runsp_lapw -dm -orb -ec 0.0001
>
> min -I -j "run_lapw -I -fc 1.0 -i 40 "
>
> # run_lapw -ec 0.0001 # -p -it -cc 0.01 -fc 1 -min
>
> Looking forward to your response in this regard.
>
> with regards,
>
> On Sun, 21 Jun 2020 at 18:45, shamik chakrabarti
> <shamik15041981 at gmail.com <mailto:shamik15041981 at gmail.com>> wrote:
>
> Should I edit the optimize.job file by the following way;
>
> runsp_lapw -dm -orb -ec 0.0001 -cc 0.01 -fc 1 -min
>
> to run simultaneous optimization of force with -dm -orb switch on
>
> On Sun, 21 Jun 2020 at 13:16, shamik chakrabarti
> <shamik15041981 at gmail.com <mailto:shamik15041981 at gmail.com>> wrote:
>
> Thank you Sir. Your advice will be helpful.
>
> With regards ,
>
> On Sun, Jun 21, 2020, 12:50 Peter Blaha
> <pblaha at theochem.tuwien.ac.at
> <mailto:pblaha at theochem.tuwien.ac.at>> wrote:
>
> YES ! Force optimization is MUCH more important than
> anything else.
> Lattice parameters are usually well known from experiment
> (and more
> accurate than DFT), but atomic positions are often NOT
> well known
> experimentally.
>
> Exception: Some structures like NaCl have "fixed positions
> by symmetry".
> So you have to find out yourself, if you have forces.
>
> How to do: Simply edit optimize.job and activate the
> -min switch in
> the run_lapw line.
>
> ad 2): If your minimum is close enough to one of your
> relaxed structures: no
> However, whenever you change a,b or c, do a force
> optimization.
>
> On 6/21/20 9:01 AM, shamik chakrabarti wrote:
> > Dear Wien2k users,
> >
> > I have two queries;
> >
> > (1) Should we have to do force minimization
> *simultaneously* for each
> > step (a) V optimization, (b) c/a optimization, (c) b/a
> optimization for
> > a orthorhombic crystal?
> >
> > (2) After a, b, c optimization should we have to do
> force minimization
> > again? (I think yes!)
> >
> > with regards,
> >
> > --
> > Dr. Shamik Chakrabarti
> > Research Fellow
> > Department of Physics
> > Indian Institute of Technology Patna
> > Bihta-801103
> > Patna
> > Bihar, India
> >
> > _______________________________________________
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> >
>
> --
>
> P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna,
> A-1060 Vienna
> Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
> Email: blaha at theochem.tuwien.ac.at
> <mailto:blaha at theochem.tuwien.ac.at> WIEN2k:
> http://www.wien2k.at
> WWW: http://www.imc.tuwien.ac.at/TC_Blaha
> --------------------------------------------------------------------------
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>
>
>
> --
> Dr. Shamik Chakrabarti
> Research Fellow
> Department of Physics
> Indian Institute of Technology Patna
> Bihta-801103
> Patna
> Bihar, India
>
>
>
> --
> Dr. Shamik Chakrabarti
> Research Fellow
> Department of Physics
> Indian Institute of Technology Patna
> Bihta-801103
> Patna
> Bihar, India
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