[Wien] Fwd: not getting convergence with MBJ potential

[pascal boulet]

Hello,

It is strange that you have such a bad convergence on the energy and the
charge after that many cycles.
My feeling is that something is wrong in the input.

Have a look at the user manual. From page 205 on, there is an
explanation of the meaning of ghost bands. You have to experiment on
your chemical system to get rid of them.

Pascal


On 12/12/2011 05:21, shamik chakrabarti wrote:
> Dear wien2k users,
>
>                        Any response of my previous mail will be very
> helpful for us. Eagerly waiting for your comments.
>
> with regards,
>
> ---------- Forwarded message ----------
> From: *shamik chakrabarti* <shamikphy at gmail.com
> <mailto:shamikphy at gmail.com>>
> Date: Sun, Dec 11, 2011 at 5:42 PM
> Subject: not getting convergence with MBJ potential
> To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at
> <mailto:wien at zeus.theochem.tuwien.ac.at>>
>
>
> Dear wien2k users,
>
>                        I am trying to simulate electronic structure of
> a charge transfer insulator. Our system consists of a unit cell having
> 56 atoms and we are using 14 k-points. As GGA+U method was failed to
> reproduce the proper band gap (in fact much less than the
> experimentally obtained one) we have opted for MBJ potential.
> *Initially the mixing parameter was set to 0.2 and we got Ghost band
> error after few iterations. Hence we reduce the mixing parameter to
> 0.15.* Until now still it has shown no error except some extra message
> in case.dayfile. I am giving those messages below. So far e.c. & c.c
> were achieved up to 2.239... & 5.4599 respectively and already 36
> iterations are over. My questions are:
>
> (1) Is it ok to set up a mixing parameter of 0.15 that is with it, is
> it possible to reach convergence?
>
> (2) As plain GGA takes around 80 iterations to converge, is it that
> MBJ potential will take much higher than that as we know it is always
> hard to get convergence with this method?
>
> (3) what are the meanings of the given messages below:
>
>   lapw2 -c -up   -vresp (17:12:13) >   lapw1  -c -dn    (16:19:33)
> 10848.369u 98.026s 52:39.78 346.4%0+0k 0+1099920io 0pf+0w
> >   lapw1  -c -up    (15:26:49) 10864.462u 99.082s 52:44.39 346.4%0+0k
> 0+1100232io 0pf+0w
> 460.324u 151.313s 6:52.62 148.2%0+0k 0+732368io 0pf+0w
>  -5.956509016536202E-002
>   3.325214690385789E-002 -9.166205529297161E-002 tauwrong=
>  int:rho,tauw,grho,g2rho  2.146196813781874E-002  1.287982148952303E-002
>  -4.564940741427861E-002
>   3.061850458947012E-002 -5.357427363703868E-002 tauwrong=
>  int:rho,tauw,grho,g2rho  1.778719641126464E-002
>  1.317651193616000E-002        *what is tauwrong?*
>  -4.561631481999567E-002
>   3.051935798833875E-002 -5.372842413400847E-002 tauwrong=
>  int:rho,tauw,grho,g2rho  1.783702549056333E-002  1.305474408433668E-002
>  -2.872847342414767E-002
>   2.625149916992486E-002 -2.271097056901070E-002 tauwrong=
>  int:rho,tauw,grho,g2rho  1.456340274765583E-002  1.183001700580401E-002
>  -2.843529510619935E-002
>   2.607602777746414E-002 -2.279192386903682E-002 tauwrong=
>  int:rho,tauw,grho,g2rho  1.462794826548238E-002  1.162089194449066E-002
>  -1.211083415464120E-002
> ..........................................
> ..........................................
> >   lapw0 (15:19:56)  sphere:rho,tauw,grho,g2rho   7.46875999972237  
>      180.956718336004     
> >   lapw0 -grr (15:15:10) 315.375u 93.253s 4:45.73 143.0%0+0k
> 0+................
>
>  
> Any response in this regard will be very helpful for us. Thanks in
> advance.
>
> with regards,
> -- 
> Shamik Chakrabarti
> Senior Research Fellow
> Dept. of Physics & Meteorology
> Material Processing & Solid State Ionics Lab
> IIT Kharagpur
> Kharagpur 721302
> INDIA
>
>
>
> -- 
> Shamik Chakrabarti
> Senior Research Fellow
> Dept. of Physics & Meteorology
> Material Processing & Solid State Ionics Lab
> IIT Kharagpur
> Kharagpur 721302
> INDIA
>
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien

-- 
Dr. pascal Boulet, computational chemist
University of Aix-Marseille I 
Laboratoire Chimie Provence, UMR 6264
Group of Theoretical Chemistry
Avenue Normandie-Niemen
13397 Marseille Cedex 20
France
**********
Tel. (+33) (0)413.55.18.10
Fax. (+33) (0)413.55.18.50
**********
http://www.lc-provence.fr
https://sites.google.com/a/univ-provence.fr/pb-comput-chem
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