[Wien] VK-COUL not well converged: Increase GMAX or decrease NCON

[tran at theochem.tuwien.ac.at]

NCON is a parameter in case.in0 for the calculation of the Coulomb
potential. I think it is better not changing it.

On Sunday 2019-08-25 12:49, Dr. K. C. Bhamu wrote:

>Date: Sun, 25 Aug 2019 12:49:25
>From: Dr. K. C. Bhamu <kcbhamu85 at gmail.com>
>Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
>To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
>Subject: Re: [Wien] VK-COUL not well converged: Increase GMAX or decrease NCON
>
>Dear Tran,
>Thanks for explaining the meaning of warnings.
>Yes,  warning disappears by  increasing Gmax to 14.
>
>What is mean by NCON?
>In which file it is written and is there any batch command to increase it?
>
>Regards
>Bhamu
>
>On Sun, Aug 25, 2019 at 4:17 PM <tran at theochem.tuwien.ac.at> wrote:
>      This is a warning from lapw0, which indicates that the Fourier expansion
>      of the Coulomb potential may not be well converged. Increase GMAX in
>      case.in2 to 16 to see if this warning disappears.
>
>
>      On Sunday 2019-08-25 12:10, Dr. K. C. Bhamu wrote:
>
>      >Date: Sun, 25 Aug 2019 12:10:49
>      >From: Dr. K. C. Bhamu <kcbhamu85 at gmail.com>
>      >Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
>      >To: A Mailing list for WIEN2k users <Wien at zeus.theochem.tuwien.ac.at>
>      >Subject: [Wien] VK-COUL not well converged: Increase GMAX or decrease NCON
>      >
>      >Dear Experts,
>      >We are running a GGA-PBE calculation on a cubic double perovskite on Wien2k_19.1 with intel compilers with
>      >
>      > 8     10   6   ELPA pxq hm (R-MT*K-MAX,MAX L IN WF,V-NMT,lib,gridshape,hm/lm)
>      >GMAX=12
>      >We are getting VK-COUL error.
>      >
>      >Exact warning is this:  VK-COUL not well converged: Increase GMAX or decrease NCON
>      >There is no information on mailing list and UG on this warning.
>      >Could someone please explore the meaning of these warnings?
>      >
>      >PS: Running scf with dense k-mesh on a scf that was finished with Wien2k_18.2.
>      >
>      >regards
>      >Bhamu
>      >
>      >
>      >_______________________________________________
>      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
>
>
>