[Wien] Fwd: not getting convergence with MBJ potential
pascal boulet
pascal.boulet at univ-provence.fr
Mon Dec 12 09:01:37 CET 2011
Dear Dr. Chakrabarti,
All right. So, another idea: could it be that you restarted your m-BJ
calculation using the converged GGA or GGA+U density? I ran into these
kinds of troubles several times. I found it preferable to start from
scratch...
Hope this help,
Pascal
On 12/12/2011 08:45, shamik chakrabarti wrote:
> Dear Dr. Pascal,
>
> As we were getting Ghost band error due to large
> charge fluctuation during initial cycle *we have reduced the mixing
> parameter from 0.2 to 0.15 & hence thereafter we have not received
> ghost band error yet.*
>
> As long as variation of RMT is concerned the variation is only from
> 1.7 to 2.01 in the structure.
>
> So far there is no energy equivalence between a local orbital and
> overall energy parameter which can induce ghost band error.
>
> Also we have achieved convergence of -0.000034 with plain GGA and only
> with MBJ potential we are getting the convergence problem and again
> plain GGA and also GGA+U have not given the proper electronic structure.
>
> As far as the structure is concerned we are very much sure about its
> structural parameters as they are giving the same XRD as experiment
> when the positional coordinates and lattice parameters of the 56 atom
> cell were put into a software powdcell.
>
> looking forwards to your comments.
>
> with regards,
> On Mon, Dec 12, 2011 at 12:26 PM, pascal boulet
> <pascal.boulet at univ-provence.fr
> <mailto:pascal.boulet at univ-provence.fr>> wrote:
>
> 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>
> > <mailto: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>
> > <mailto: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
> <mailto: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
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> * Français - détecté
> * Anglais
> * Français
>
> * Anglais
> * Français
>
> <javascript:void(0);>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> <mailto:Wien at zeus.theochem.tuwien.ac.at>
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
>
>
>
> --
> 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
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
More information about the Wien
mailing list