[CP2K-user] [CP2K:12564] Problems with RPBE

[Thomas Kühne]

Dear Wan-Lu, 

since RPBE just contains a modified exchange enhancement factor to mimic 
rPBE yet still fullfilling the local Oxford-Lieb bound, IMHO you simply missing 
plain conventional PBE correlation. 

Cheers, 
Thomas

> Am 28.11.2019 um 07:35 schrieb Wan-Lu Li <wanlu... at gmail.com>:
> 
> Dear CP2K users,
> I'm wondering if I implemented RPBE right or not. I compared the inter-molecular interaction of water dimers using B97M_rV and RPBE functionals. But I found that the binding energy difference is quiet large. The energy based on B97M_rV is 5.19 kcal/mol, while RPBE is only 1.65 kcal/mol. I'm sure the B97M_rV result is correct. So why RPBE underestimate the energy quite large. I attach the input for RPBE (one water) here, please help me check it. Thanks in advance!
> Best regards,
> Wanlu
> 
> &FORCE_EVAL
>         METHOD QS
>         &DFT
>                 BASIS_SET_FILE_NAME BASIS_MOLOPT
>                 POTENTIAL_FILE_NAME GTH_POTENTIALS
>                 &MGRID
>                         CUTOFF 1200
>                         REL_CUTOFF 60
>                 &END MGRID
>                 &QS
>                         EPS_DEFAULT 1.0E-12
>                 &END QS
>                 &SCF
>                    EPS_SCF 1.0E-6 
>                    &OT ON
>                            MINIMIZER DIIS
>                    &END OT
>                    &OUTER_SCF ON  
>                            MAX_SCF 5
>                            EPS_SCF 1.0E-6
>                    &END OUTER_SCF
>                   &END SCF
>                   &XC
>                         &XC_FUNCTIONAL
>                                 &LIBXC
>                                         FUNCTIONAL GGA_X_RPBE
>                                 &END LIBXC
>                         &END XC_FUNCTIONAL
>                         &XC_GRID
>                                 XC_DERIV NN50_SMOOTH
>                         &END XC_GRID
>                  &END XC
>                  &POISSON
>                          PERIODIC none
>                          POISSON_SOLVER wavelet
>                  &END POISSON
>         &END DFT
>         &SUBSYS
>                 &CELL
>                         ABC 20.0 20.0 20.0
>                         ALPHA_BETA_GAMMA 90.0 90.0 90.0
>                         PERIODIC NONE
>                 &END CELL
>                 &COORD
>                 O   1.350625   0.111469   0.000000
>                 H   1.680398  -0.373741  -0.758561
>                 H   1.680398  -0.373741   0.758561
>                 &END COORD
>                 &TOPOLOGY
>                         &CENTER_COORDINATES
>                         &END CENTER_COORDINATES
>                 &END TOPOLOGY
>                 &KIND O
>                         BASIS_SET TZVP-MOLOPT-GTH
>                         POTENTIAL GTH-PBE-q6
>                 &END KIND
>                  &KIND H
>                          BASIS_SET TZVP-MOLOPT-GTH
>                          POTENTIAL GTH-PBE-q1
>                 &END KIND
> 
>          &END SUBSYS
> &END FORCE_EVAL
> 
> &GLOBAL
>         PROJECT Dimer_SP
>         RUN_TYPE Energy
> &END GLOBAL
> 
> -- 
> 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 cp... at googlegroups.com <mailto:cp... at googlegroups.com>.
> To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/CA%2BSPXOjcGhVs1e38n5R2zox3%2BF4mNqg_FcFPRoVWDhiPeEG3ag%40mail.gmail.com <https://groups.google.com/d/msgid/cp2k/CA%2BSPXOjcGhVs1e38n5R2zox3%2BF4mNqg_FcFPRoVWDhiPeEG3ag%40mail.gmail.com?utm_medium=email&utm_source=footer>.



==============================
Thomas D. Kühne
Dynamics of Condensed Matter
Chair of Theoretical Chemistry
University of Paderborn
Warburger Str. 100
D-33098 Paderborn
Germany
tdku... at mail.upb.de
+49/(0)5251/60-5726

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20191128/4bd501d4/attachment.htm>