[CP2K:8808] very long calculation time

hut... at chem.uzh.ch hut... at chem.uzh.ch
Mon Mar 13 11:10:58 UTC 2017


Hi

you still didn't answer my question:

is your 'long' simulation time caused by: 

- slow convergence of geometry optimization 
     ==> Numbers please.
- slow convergence of SCF 
     ==> How many iterations? Did it converge at all?
- high CPU time per SCF cycle? 
     ==> Give us some numbers. It is impossible to say something
         without having any information.

Do you really need LSD? 

regards

--------------------------------------------------------------
Juerg Hutter                         Phone : ++41 44 635 4491
Institut für Chemie C                FAX   : ++41 44 635 6838
Universität Zürich                   E-mail: hut... at chem.uzh.ch
Winterthurerstrasse 190
CH-8057 Zürich, Switzerland
---------------------------------------------------------------

-----cp... at googlegroups.com wrote: -----To: cp2k <cp... at googlegroups.com>
From: Amin 
Sent by: cp... at googlegroups.com
Date: 03/13/2017 12:07PM
Subject: Re: [CP2K:8808] very long calculation time

To add up some thing: I think that is because of the slow convergence of the SCF.The interesting point is that with 48 atoms in my supercell, SCF converged in less than one hour! but now with 192 atoms, it takes more than a week (even more!, because it hasn't converged yet!)

On Monday, March 13, 2017 at 11:57:14 AM UTC+1, Amin wrote:Thank you very much for your swift reply.I am replicating a calculation that has been done previously by VASP. at first I tried to calculate adsorption energy with 48 atoms in my supercell, but there was a major difference between my results and the previous one. Then I modified my structure to include more atoms. I'll try to apply your suggestions but I also attach my complete input file in case that it might help to give a better perspective. -Because of this point that calculation stopped after reaching the wall-time, I set the new input file to use the Restart wave-function. But I'm not sure that it's been done correctly! Sorry if my questions are so rudimentary! 
I sincerely appreciate your time and considerations.

&GLOBAL  PROJECT  Chemisorption-newconf  RUN_TYPE GEO_OPT  PRINT_LEVEL LOW  EXTENDED_FFT_LENGTHS&END GLOBAL
&FORCE_EVAL  METHOD Quickstep               &DFT    WFN_RESTART_FILE_NAME Chemisorption-newconf-RESTART.wfn     BASIS_SET_FILE_NAME  BASIS_MOLOPT    POTENTIAL_FILE_NAME  GTH_POTENTIALS    LSD    CHARGE 0    MULTIPLICITY 1    &MGRID        CUTOFF 800        REL_CUTOFF 60    &END MGRID    &QS        METHOD GPW        EPS_DEFAULT 1.0E-12    &END QS    &POISSON        PERIODIC XYZ    &END POISSON    &SCF                              SCF_GUESS RESTART      EPS_SCF 1.0E-6      MAX_SCF 100      &OT        PRECONDITIONER FULL_ALL        MINIMIZER CG      &END OT      &OUTER_SCF        MAX_SCF 20        EPS_SCF 1.0E-6      &END OUTER_SCF    &END SCF    &XC                             &XC_FUNCTIONAL PBE      &END XC_FUNCTIONAL      &VDW_POTENTIAL        DISPERSION_FUNCTIONAL PAIR_POTENTIAL        &PAIR_POTENTIAL                TYPE DFTD3(BJ)                REFERENCE_FUNCTIONAL PBE                CALCULATE_C9_TERM .FALSE.                PARAMETER_FILE_NAME dftd3.dat                R_CUTOFF 15.0        &END PAIR_POTENTIAL      &END VDW_POTENTIAL    &END XC  &END DFT
  &SUBSYS    &CELL      ABC 15.138 15.138 30.0000      PERIODIC XYZ     &END CELL    &TOPOLOGY      COORD_FILE_FORMAT XYZ      COORD_FILE_NAME  ./Anatase001-192.xyz    &END    &KIND C      ELEMENT C      BASIS_SET DZVP-MOLOPT-SR-GTH      POTENTIAL GTH-PBE-q4    &END KIND     &KIND Ti      ELEMENT Ti      BASIS_SET DZVP-MOLOPT-SR-GTH      POTENTIAL GTH-PBE-q12    &END KIND    &KIND O      ELEMENT O      BASIS_SET DZVP-MOLOPT-SR-GTH      POTENTIAL GTH-PBE-q6    &END KIND  &END SUBSYS  &PRINT        &TOTAL_NUMBERS ON        &END TOTAL_NUMBERS  &END PRINT&END FORCE_EVAL&MOTION        &GEO_OPT          OPTIMIZER BFGS          MAX_FORCE 4.50000000E-004        &END        &CONSTRAINT          &FIXED_ATOMS                LIST 0..95          &END FIXED_ATOMS        &END CONSTRAINT&END MOTION
On Monday, March 13, 2017 at 11:35:58 AM UTC+1, jgh wrote:Hi



is your 'long' simulation time caused by:



- slow convergence of geometry optimization

- slow convergence of SCF

- high CPU time per SCF cycle?



To improve CPU time per SCF I would suggest (guessing without 

knowing your full input)

- use only MOLOPT-SR basis sets

- reduce EPS_DEFAULT to 1.e-10

- Preconditioner -> FULL_SINGLE_INVERSE



Do you really need LSD?



regards



Juerg Hutter

--------------------------------------------------------------

Juerg Hutter                         Phone : ++41 44 635 4491

Institut für Chemie C                FAX   : ++41 44 635 6838

Universität Zürich                   E-mail: hut... at chem.uzh.ch

Winterthurerstrasse 190

CH-8057 Zürich, Switzerland

---------------------------------------------------------------



-----cp... at googlegroups.com wrote: -----To: cp2k <cp... at googlegroups.com>

From: Amin 

Sent by: cp... at googlegroups.com

Date: 03/13/2017 10:28AM

Subject: [CP2K:8806] very long calculation time



Hi all,I am trying to calculate the adsorption energy of co2 on Tio2 surface (with 192 atoms in my supercell). but the problem is that it takes too long time to be calculated. I'm using 80 processors (2.8 GHz - each) but as I set the wall time for 7 days, it reached that wall time and calculations stopped. I have done similar calculations for fewer atoms (48,98) in super cell but in those cases (even with fewer CPUs) it takes at most 1 day to calculate everything. Because I'm a beginner in CP2K, I don't have any idea weather this amount of time for calculation is reasonable. I have attached critical parts of my input file. I will be grateful if someone gives a comment regarding my question.- Any suggestion for decreasing the calculation time with the same number of atoms is warmly appreciated.. :)

&GLOBAL  PROJECT  Ch  RUN_TYPE GEO_OPT  PRINT_LEVEL LOW  EXTENDED_FFT_LENGTHS&END GLOBAL

&FORCE_EVAL  METHOD Quickstep       &DFT    BASIS_SET_FILE_NAME  BASIS_MOLOPT    POTENTIAL_FILE_NAME  GTH_POTENTIALS    LSD    CHARGE 0    MULTIPLICITY 1    &MGRID        CUTOFF 800        REL_CUTOFF 60    &END MGRID    &QS        METHOD GPW        EPS_DEFAULT 1.0E-12    &END QS    &POISSON        PERIODIC XYZ    &END POISSON    &SCF                            SCF_GUESS ATOMIC      EPS_SCF 1.0E-6      MAX_SCF 100      &OT        PRECONDITIONER FULL_ALL        MINIMIZER CG      &END OT      &OUTER_SCF        MAX_SCF 20        EPS_SCF 1.0E-6      &END OUTER_SCF    &END SCF    &XC                  &XC_FUNCTIONAL PBE      &END XC_FUNCTIONAL      &VDW_POTENTIAL        DISPERSION_FUNCTIONAL PAIR_POTENTIAL        &PAIR_POTENTIAL                TYPE DFTD3(BJ)                REFERENCE_FUNCTIONAL PBE                CALCULATE_C9_TERM .FALSE.                PARAMETER_FILE_NAME dftd3.dat                R_CUTOFF 15.0        &END PAIR_POTENTIAL      &END VDW_POTENTIAL    &END XC  &END DFT

  &SUBSYS    &CELL      ABC 15.138 15.138 30.0000      PERIODIC XYZ     &END CELL    &TOPOLOGY      COORD_FILE_FORMAT XYZ      COORD_FILE_NAME  ./Anatase001-192.xyz    &END

&END FORCE_EVAL&MOTION        &GEO_OPT          OPTIMIZER BFGS          MAX_FORCE 4.50000000E-004        &END        &CONSTRAINT          &FIXED_ATOMS                LIST 0..95          &END FIXED_ATOMS        &END CONSTRAINT&END MOTION









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