[CP2K-user] nonscc dftb problem

[simin pahlavi]

Dear cp2k users,
I am trying to perform dftb on graphite using cp2k and I have some 
questions witch I appreciate any help and comments in advance.
When I am trying to perform dftb using the following input if I let the 
cutoff in MGRID section to default value (1 Ry)  calculations stop
after 15 steps without writing output, while when I set cutoff to 400 Ry it 
works fine. I am new and I am not sure if 400 Ry make sense on nonscc dftb 
at all.
1) If my input is set up correctly for these type of calculation.
2) Normally what the range of cuttof in nonscc dftb should be?
3) how should I decide on type of mixing , based on convergence speed up 
only?
Thanks in advance,
Regards,
Simin



 &MD
   ENSEMBLE NPT_I
   STEPS 5
   TIMESTEP 0.5
   TEMPERATURE 2000

   &BAROSTAT
    PRESSURE [GPa] 50
    TIMECON  1000
   &END BAROSTAT

   &THERMOSTAT
    TYPE CSVR
    &CSVR
    TIMECON 100.
    &END CSVR
   &END THERMOSTAT
 &END MD
  
&END MOTION

&FORCE_EVAL
 STRESS_TENSOR DIAGONAL_ANALYTICAL
 METHOD Quickstep
 &DFT
  CHARGE 0
  MULTIPLICITY 1
#    &MGRID
#       CUTOFF [Ry] 400
#    &END
    &QS
     METHOD DFTB
      &DFTB
        SELF_CONSISTENT    F
        &PARAMETER
        PARAM_FILE_PATH  ./pbc-0-3
        SK_FILE C C C-C.skf
        &END PARAMETER
        &END DFTB
        EXTRAPOLATION USE_GUESS  

    &POISSON
      PERIODIC XYZ
      PSOLVER PERIODIC
     &END

    &SCF
      SCF_GUESS ATOMIC
      ADDED_MOS 100
     
      &DIAGONALIZATION
        ALGORITHM STANDARD
        EPS_ADAPT 0.01      !defult value is zero
      &END DIAGONALIZATION

      &SMEAR  ON
            METHOD FERMI_DIRAC
            ELECTRONIC_TEMPERATURE [K] 1000
         &END SMEAR

         &MIXING
            METHOD BROYDEN_MIXING
            ALPHA 0.2
            BETA 1.5
            NBROYDEN 8
         &END MIXING

       &PRINT
          &RESTART OFF
          &END RESTART
       &END PRINT

      MAX_SCF  10
    &END SCF

    &KPOINTS
      KPOINT 0 0 0 1
      SCHEME GAMMA
      FULL_GRID ON
    &END

     &PRINT

       &MULLIKEN
         &EACH
         MD 1
         &END EACH
       &END MULLIKEN
   

 &END PRINT
    &END DFT
 
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