[Thermo_pw-forum] Thermo_pw-forum Digest, Vol 10, Issue 2

[Andrea Dal Corso]

Unfortunately to calculate the geometry at a given temperature is as
difficult as to calculate the anharmonic properties. You need the
vibrational free energy for several geometries, that is the phonon
dispersions at several geometries. 
For thermo_pw this is a complex calculation and it works only for a few
crystal systems. You can try to simplify as much as possible the
calculations using lmurn=.TRUE., but definitively you must start with
some simpler project and to learn how the code work before trying such a
difficult calculation.

HTH,

Andrea




On Mon, 2016-05-09 at 16:49 +0200, agbaoye at physics.unaab.edu.ng wrote:
> > Send Thermo_pw-forum mailing list submissions to
> > 	thermo_pw-forum at qeforge.qe-forge.org
> >
> > To subscribe or unsubscribe via the World Wide Web, visit
> > 	http://qeforge.qe-forge.org/mailman/listinfo/thermo_pw-forum
> > or, via email, send a message with subject or body 'help' to
> > 	thermo_pw-forum-request at qeforge.qe-forge.org
> >
> > You can reach the person managing the list at
> > 	thermo_pw-forum-owner at qeforge.qe-forge.org
> >
> > When replying, please edit your Subject line so it is more specific
> > than "Re: Contents of Thermo_pw-forum digest..."
> >
> >
> > Today's Topics:
> >
> >    1. Re: How to set temperature for band structure calculation
> >       (Andrea Dal Corso)
> >
> >
> > ----------------------------------------------------------------------
> >
> > Message: 1
> > Date: Fri, 06 May 2016 12:16:29 +0200
> > From: Andrea Dal Corso <dalcorso at sissa.it>
> > Subject: Re: [Thermo_pw-forum] How to set temperature for band
> > 	structure calculation
> > To: thermo_pw-forum at qeforge.qe-forge.org
> > Message-ID: <1462529789.3069.21.camel at ulisse.cm.sissa.it>
> > Content-Type: text/plain; charset="UTF-8"
> >
> > On Thu, 2016-05-05 at 21:46 +0200, agbaoye at physics.unaab.edu.ng wrote:
> >> Good day Sir
> >> I intend calculating band structure at specified temperature on
> >> thermo_pw,
> >> having looked at the Doc file, i could not find the temperature variable
> >> for band calculation, except the tmin and tmax.
> >>
> >> Sir, is there a possibility of calculating band structure at a specific
> >> temperature using thermo_pw, i will appreciate if you can guide me on
> >> how
> >> to do this
> >>
> >> Thank you very much Sir
> >
> > Dear Agbaoye Ridwan Olamide,
> >
> > You can calculate the band structure at the geometry that corresponds to
> > a given temperature that you can calculate by using thermo_pw. The
> > effect of thermal expansion on the band structure can be seen with this
> > approach.
> > However the temperature dependence of the band structure has often
> > important contributions from electron-phonon interactions. These effects
> > are not included in thermo_pw and you should use other packages for this
> > purpose.
> >
> > HTH,
> >
> > Andrea
> >
> >
> >>
> >> Agbaoye Ridwan Olamide
> >> Federal University of Agriculture, Abeokuta
> >>
> >> _______________________________________________
> >> Thermo_pw-forum mailing list
> >> Thermo_pw-forum at qeforge.qe-forge.org
> >> http://qeforge.qe-forge.org/mailman/listinfo/thermo_pw-forum
> >
> >
> >
> >
> > ------------------------------
> >
> > _______________________________________________
> > Thermo_pw-forum mailing list
> > Thermo_pw-forum at qeforge.qe-forge.org
> > http://qeforge.qe-forge.org/mailman/listinfo/thermo_pw-forum
> >
> >
> > End of Thermo_pw-forum Digest, Vol 10, Issue 2
> > **********************************************
> >
> Thank you very much for your response
> 
> I tried optimizing the geometry at a particular temperature using tmin=100
> within the what='mur_lc' thermo control to determine the minimum volume at
> 100K but the optimized volume seems to be the same with when tmin=10, i
> guess i have not understood the concept of doing geometry at a particular
> temperature.
> 
> Please help me verify 1. The variable required to specify temperature on
> thermo
> 2. i tried using the thermo control what='mur_lc_t' but i realized that it
> calculates a lot of properties which i may not need, all i need for now is
> the optimized geometry at a particular temperature.
> 
> Thank you very much in anticipation for your response
> 
> Agbaoye Ridwan Olamide
> Federal University of Agriculture, Abeokuta
> 
> 
> 
> 
> _______________________________________________
> Thermo_pw-forum mailing list
> Thermo_pw-forum at qeforge.qe-forge.org
> http://qeforge.qe-forge.org/mailman/listinfo/thermo_pw-forum