[CP2K-user] Transition form PBE0 to PBE with CUTOFF_RADIUS 6.0: How to choose the vdW POTENTIAL R_CUTOFF?

[Vyacheslav Bryantsev]

Dear CP2K Community,

I am using truncated Coulomb operator with long range correction to go 
smoothly from PBE0 to PBE with CUTOFF_RADIUS 6.0 (the &XC block is defined 
below).

My question is how one should define the vdW_POTENTIAL R_CUTOFF parameter 
in this case. Here I am using PBED3 for PBE0 with R_CUTOFF 40.0. 
I assume that beyond CUTOFF_RADIUS 6.0 it would still be applied based on 
PBE0, not PBE. Is there a way to make vdW_POTENTIAL consistent for 
different distances, or perhaps, this is not a big deal? Please advise.

Another ulrelated question for setting up PBE0 calculations.
In several tutorials online, EPS_SCHWARZ 1.0E-6, was used.
However, in this forum, EPS_SCHWARZ 1.0E-10 or even 1.0E-12 was 
recommended. Since I would like to generate a trajectory of several tens on 
ps, having low threshold on this parameter is unpractical. Would 
EPS_SCHWARZ 1.0E-6 be still a good compromise?

Thank you,
Slava

   &XC
       &XC_FUNCTIONAL
          &PBE
             SCALE_X 0.75
             SCALE_C 1.0
          &END PBE
          &PBE_HOLE_T_C_LR
             CUTOFF_RADIUS 6.0
             SCALE_X 0.25
          &END PBE_HOLE_T_C_LR
       &END XC_FUNCTIONAL
       &vdW_POTENTIAL
         DISPERSION_FUNCTIONAL PAIR_POTENTIAL
         &PAIR_POTENTIAL
            R_CUTOFF 40.0
            TYPE DFTD3
            PARAMETER_FILE_NAME            dftd3.dat
            REFERENCE_FUNCTIONAL PBE0
         &END PAIR_POTENTIAL
       &END vdW_POTENTIAL
       &HF
           &SCREENING
             EPS_SCHWARZ 1.0E-6
             SCREEN_ON_INITIAL_P FALSE
           &END SCREENING
           &INTERACTION_POTENTIAL
             POTENTIAL_TYPE TRUNCATED
             CUTOFF_RADIUS 6.0
             T_C_G_DATA ./t_c_g.dat
           &END INTERACTION_POTENTIAL
           &MEMORY
              MAX_MEMORY 3000
              EPS_STORAGE_SCALING 0.1
          &END MEMORY
          FRACTION 0.25
       &END HF
    &END XC


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