[Wien] Large forces appeared when calculating total energy after structure optimization

[Peter Blaha]

All we can say is that you have done somewhere a mistake.

It is important that you not just "describe" what you did, but list the 
actual commands.

Did you use the same   runsp command during "optimization" ?

Could it be that you restarted the final SCF from "scratch" ???
In DFT+U you might have ended up in a different state when starting with 
dstart densities without *dmat* files.

Compare your total energies of best optimization and the final SCF. 
Which one is lower ?

Am 06.02.2021 um 12:47 schrieb shamik chakrabarti:
> Dear Wien2k users,
>                                  I have initially optimized an 
> orthorhombic crystal system structurally (simultaneous optimization of 
> a,b,c & coordinates & then optimization of coordinates again by taking 
> optimized lattice parameters). However, after taking the optimized 
> structure when I simulate the total energy with converged SCFby running 
> the command  runsp_lapw -dm -orb -fc 1.0 -ec 0.0001 -cc 0.0001, I have 
> found that large forces ~ 40 mRy/a.u.  appeared for few atoms.
> 
> My queries are (a) why this happens? & (b) what is the remedy? (c) 
> whether DOS is reliable in this case?
> 
> *However, the simulated voltage as calculated from the total energy of 
> the system has been matched with the experiment very well.
> *
> 
> Looking forward to hearing from you.
> 
> with regards,
> -- 
> Dr. Shamik Chakrabarti
> Research Fellow
> Department of Physics
> Indian Institute of Technology Patna
> Bihta-801103
> Patna
> Bihar, India
> 
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
> 

-- 
--------------------------------------------------------------------------
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    WIEN2k: http://www.wien2k.at
WWW:   http://www.imc.tuwien.ac.at
-------------------------------------------------------------------------