[Wien] phonon calculation

[Yundi Quan]

Hi, I checked my calculations. And I can confirm that RMT, RKMAX does not
change. The density seems to have converged at least according to the
convergence criterion.
*:ENERGY convergence:  1 0.000001 .0000004300000000
:CHARGE convergence:  1 0.0001 -.0000820*
:FORCE convergence: 1 0.1 .051 XCO .010 XCO .004 XC
I also checked the structure file atom by atom and did not find any
discrepancy.

The only thing which I am not quite sure is the command I use
min -i 1000 -s 4 -j 'runsp_lapw -I -i 4000 -fc 1.0 -p -it '
I did not specify energy convergence criteria in my min calculation. I think
that is the reason for the huge total force on atoms.


Yundi


2011/9/27 Laurence Marks <L-marks at northwestern.edu>

> Some guesses:
> # You changed RMT, RKMAX and the earlier ones were not good enough.
> # You are not looking at a converged density.
> # You made a mistake when copying the struct files.
>
> 99.99% probability that this is a "user error", I.e. you did something
> wrong.
> On Sep 27, 2011 7:54 AM, "Yundi Quan" <quan at ms.physics.ucdavis.edu> wrote:
> > Hi, Thanks for your suggestion. However, it turns out that I did use -fc
> > 0.1. But still the force is very large. I paste the end of scf file
> below.
> >
> >
> > FGL001: 1.ATOM -5.623000000 0.000000000 -0.010500000
> > total forces
> > :FGL002: 2.ATOM 0.000000000 0.000000000
> > 0.000000000 total forces
> > :FGL003: 3.ATOM -2.129500000 0.000000000
> > 5.691000000 total forces
> > :FGL004: 4.ATOM 33.965000000 5.442500000
> > 24.743000000 total forces
> > :FSUM : Sum of forces Fx,Fy,Fz 0.00000
> > 0.00000 0.00000
> >
> >
> > Yundi
> >
> > On Tue, Sep 27, 2011 at 12:08 AM, Stefaan Cottenier <
> > Stefaan.Cottenier at ugent.be> wrote:
> >
> >>
> >> I have another problem. After running 'min ....', I got a structure with
> >>> very small force. However, when I do another calculation with the
> >>> structure I got, the total force on each atom becomes very large. What
> >>> is the reason for this?
> >>>
> >>
> >> Check whether it mentions partial forces or total forces at the end of
> the
> >> :FOR or :FGL lines. Probably your calculation with large forces was done
> >> withouth -fc, and lists only the partial forces. Add another iteration
> with
> >> TOT changed to FOR in case.in2(c) (which is what -fc does in its last
> >> iteration).
> >>
> >> Stefaan
> >>
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