[CP2K-user] [CP2K:18550] Re: Cutoff convergence for SCAN functional

[Jürg Hutter]

Hi

Maybe:

EPS_DEFAULT  1.E-14

REL_CUTOFF   100

helps.
regards
JH

________________________________________
From: cp2k at googlegroups.com <cp2k at googlegroups.com> on behalf of Rajorshi Chattopadhyay <rajorshichat at gmail.com>
Sent: Friday, March 17, 2023 12:27 PM
To: cp2k at googlegroups.com
Subject: Re: [CP2K:18549] Re: Cutoff convergence for SCAN functional

Hello Fabian,

I thank you for your reply.

When I do cutoff convergence test with r2SCAN, I get the following energy values till 1500Ry (REL_CUTOFF:60):

Cutoff
Rel cutoff
Energy
Charge
600
60
-1125.17821812053535
-0.0000000141
700
60
-1125.17827283731867
-0.0000000147
800
60
-1125.17815235733997
-0.0000000121
900
60
-1125.17818711771633
-0.0000000128
1000
60
-1125.17816274805796
-0.0000000131
1100
60
-1125.17813293059771
-0.0000000132
1200
60
-1125.17820271100982
-0.0000000140
1300
60
-1125.17820271126402
-0.0000000141
1400
60
-1125.17817412922477
-0.0000000128
1500
60
-1125.17817458499053
-0.0000000139

I find that the convergence is only till 10**-3 Ha.


On Fri, 17 Mar 2023 at 10:18, Fabian <belleflamme.fabian at gmail.com<mailto:belleflamme.fabian at gmail.com>> wrote:
Dear Rajorshi,

The original SCAN functional is known to be very sensitive to the integration grid used during calculation.
An easy fix would be to switch to r2SCAN (acs.jpclett.0c02405) instead:

      &XC
        &XC_FUNCTIONAL
          &MGGA_X_R2SCAN
          &END
          &MGGA_C_R2SCAN
          &END
        &END
      &END XC

Typically, the cutoff should be converged at 1200Ry with SCAN.

Kind regards,
Fabian
Rajorshi Chattopadhyay schrieb am Freitag, 17. März 2023 um 00:11:52 UTC+1:
Dear all,

I am trying to do cutoff convergence with the SCAN functional in a aqueous H2O-H2SO4 system. I need an energy convergence of 10**-6 Ha or lower. However, I find that even at a cutoff of 4000Ry (REL_CUTOFF:60), energy convergence is only 10**-4 Ha. The input script is as follows:


&GLOBAL

    PROJECT Sulphate_amb_dens

    RUN_TYPE ENERGY_FORCE

    PRINT_LEVEL MEDIUM

&END GLOBAL

&FORCE_EVAL

&DFT

      MULTIPLICITY 1

      BASIS_SET_FILE_NAME ./BASIS_MOLOPT

      POTENTIAL_FILE_NAME ./SCAN_POTENTIALS

  &MGRID

      CUTOFF 3800

      REL_CUTOFF 60

      NGRIDS 4

  &END MGRID

  &SCF

     SCF_GUESS ATOMIC

     MAX_SCF 3000

     EPS_SCF 1.00000000E-007

     &OT

        MINIMIZER DIIS

        PRECONDITIONER FULL_SINGLE_INVERSE

     &END OT

  &END SCF

  &XC

     &XC_FUNCTIONAL

         &LIBXC

          FUNCTIONAL MGGA_X_SCAN

         &END LIBXC

         &LIBXC

           FUNCTIONAL MGGA_C_SCAN

           &END LIBXC

     &END XC_FUNCTIONAL

    &END XC

   &END DFT

  &SUBSYS

    &TOPOLOGY

     &CENTER_COORDINATES TRUE

     &END CENTER_COORDINATES

    &END TOPOLOGY


    &CELL

       ABC 12.32 12.32 12.32

       PERIODIC XYZ

    &END CELL

    &COORD

      @include ../coord_eql

   &END COORD

   &KIND H

      BASIS_SET DZVP-MOLOPT-SR-GTH

      POTENTIAL GTH-SCAN-q1

   &END

   &KIND O

      BASIS_SET DZVP-MOLOPT-SR-GTH

      POTENTIAL GTH-SCAN-q6

   &END

  &KIND S

      BASIS_SET DZVP-MOLOPT-GTH

      POTENTIAL GTH-SCAN-q6

   &END


  &END SUBSYS

 &END FORCE_EVAL


I use the pseudopotentials provided by Dr. Joerg Hutter in his github.

Am I missing something in the input script ? Is it possible to achieve such tight energy convergences using SCAN the functional?

I thank you in advance for your help/suggestions.

--
With Regards,
Rajorshi Chattopadhyay,
PhD Researcher in Mineralogy/Crystallography,
Institut für Geologie und Mineralogie,
Universität zu Köln, Germany


--
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com<mailto:cp2k+unsubscribe at googlegroups.com>.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/a68b39f8-10cc-4a1f-a6a4-a3aa8c0893ffn%40googlegroups.com<https://groups.google.com/d/msgid/cp2k/a68b39f8-10cc-4a1f-a6a4-a3aa8c0893ffn%40googlegroups.com?utm_medium=email&utm_source=footer>.


--
With Regards,
Rajorshi Chattopadhyay,
PhD Researcher in Mineralogy/Crystallography,
Institut für Geologie und Mineralogie,
Universität zu Köln, Germany

​

--
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com<mailto:cp2k+unsubscribe at googlegroups.com>.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/CACTJSRfhgJHLbZRTFmKnor5O58G%3DNriRQVaHm-2KK_xbuK-gEg%40mail.gmail.com<https://groups.google.com/d/msgid/cp2k/CACTJSRfhgJHLbZRTFmKnor5O58G%3DNriRQVaHm-2KK_xbuK-gEg%40mail.gmail.com?utm_medium=email&utm_source=footer>.

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/ZR0P278MB075931AD020B7A19C3CA23E99FBD9%40ZR0P278MB0759.CHEP278.PROD.OUTLOOK.COM.