Cut-off problrm

simin pahlavi simin.... at gmail.com
Wed May 2 15:14:23 UTC 2018


Thank you very much for your helps Matteu.
Regards
Simin
On Tuesday, May 1, 2018 at 10:11:48 PM UTC+2, Matt W wrote:
>
> Hi again,
>
> EPS_SCF is the convergence of the SCF cycle. This is the convergence of 
> the energy given a set of parameters (geometry, cutoff, basis set etc).
>
> We are talking about convergence with respect to the cutoff parameter.
>
> Matt
>
> On Tuesday, May 1, 2018 at 8:47:02 PM UTC+1, simin pahlavi wrote:
>>
>> Hello,
>> Thank you very much Matheu for your answer.
>> Maybe I am misunderstood, but I thought we call convergence where the 
>> energy does not change in the accuracy range of eps_scf 10-7.
>> what do you mean by  1 meV per formula unit ?
>> Could you please clear this out?
>> Best regards
>> Simin
>>
>> On Monday, April 30, 2018 at 6:47:11 PM UTC+2, Matt W wrote:
>>>
>>> Oh, come on now. Typical papers with PW codes report convergence to 1 
>>> meV per formula unit or similar. I think you are quite safe! 
>>>
>>> It is a definite improvement, no?
>>>
>>> On Monday, April 30, 2018 at 2:10:45 PM UTC+1, simin pahlavi wrote:
>>>>
>>>> Dear Matheu,
>>>> As you guide, I changed the     XC_SMOOTH_RHO NONE     XC_DERIV PW
>>>> parts , and also I am asking for ngrids 1. but still I dont see a clear 
>>>> convergence in cuttoff.  Is it possible that there is a random number 
>>>> generator somewhere in my input?
>>>> I really appreciate any helps in advance.
>>>>
>>>>  cutoff                  energy
>>>>   50.0000000000  -230.8714667076           0
>>>>  100.0000000000  231.7994590012           0
>>>>  150.0000000000  -231.8316639575           0
>>>>  200.0000000000  -231.8369041137           0
>>>>  250.0000000000  -231.8375305477           0
>>>>  300.0000000000  -231.8377198370           0
>>>>  350.0000000000  -231.8375224535           0
>>>>  400.0000000000  -231.8375088884           0
>>>>  450.0000000000  -231.8375120028           0
>>>>  500.0000000000  -231.8375120028           0
>>>>  550.0000000000  -231.8375100426           0
>>>>  600.0000000000  -231.8375088384            0
>>>>
>>>>
>>>> &GLOBAL
>>>>  PRINT_LEVEL MEDIUM
>>>>   PROJECT HH
>>>>  RUN_TYPE ENERGY
>>>> # SEED 300
>>>> &END GLOBAL
>>>>
>>>>
>>>> &FORCE_EVAL
>>>>  METHOD Quickstep
>>>>  &DFT
>>>> #  WFN_RESTART_FILE_NAME HH
>>>>   BASIS_SET_FILE_NAME ../BASIS_MOLOPT
>>>>   POTENTIAL_FILE_NAME ../GTH_POTENTIALS
>>>>     CHARGE 0
>>>>     MULTIPLICITY 6
>>>>     &MGRID
>>>>   NGRIDS 1
>>>>   CUTOFF LT_cutoff
>>>>   REL_CUTOFF LT_rel_cutoff
>>>>   #     CUTOFF LT_cutoff 
>>>>     &END
>>>>    &QS
>>>>   #    ! use the GPW method (i.e. pseudopotential based calculations 
>>>> with the Gaussian and Plane Waves scheme).
>>>>   #    METHOD GPW 
>>>>   #    ! default threshold for numerics ~ roughly numerical accuracy of 
>>>> the total energy per electron,
>>>>   #    ! sets reasonable values for all other thresholds.
>>>>   #    EPS_DEFAULT 1.0E-10 
>>>>   #    ! used for MD, the method used to generate the initial guess.
>>>>       EXTRAPOLATION ASPC
>>>>       EPS_DEFAULT 1.0E-10
>>>> #      WF_INTERPOLATION PS
>>>> #      EXTRAPOLATION_ORDER 3
>>>>       METHOD GPW
>>>>     &END
>>>>     &POISSON
>>>>        PERIODIC XYZ ! 
>>>>     &END
>>>>  &SCF
>>>>    SCF_GUESS ATOMIC
>>>>    EPS_SCF 5.e-7
>>>>    MAX_SCF 1
>>>>       &OT
>>>>         !an accurate preconditioner suitable also for larger systems
>>>>         PRECONDITIONER FULL_SINGLE_INVERSE
>>>>         !the most robust choice (DIIS might sometimes be faster, but 
>>>> not as stable).
>>>>         MINIMIZER DIIS
>>>>       &END OT
>>>>    &OUTER_SCF
>>>>     TYPE NONE
>>>>     OPTIMIZER NONE
>>>>     EPS_SCF 5.0E-7
>>>>     MAX_SCF 1
>>>>    &END OUTER_SCF
>>>>   &END SCF
>>>>
>>>>   &XC
>>>>    &XC_FUNCTIONAL PBE
>>>>    &END XC_FUNCTIONAL
>>>>    &XC_GRID
>>>>  #   XC_SMOOTH_RHO NN50
>>>>  #   XC_DERIV NN50_SMOOTH
>>>>     XC_SMOOTH_RHO NONE
>>>>     XC_DERIV PW
>>>>
>>>>    &END XC_GRID
>>>>    &VDW_POTENTIAL
>>>>     DISPERSION_FUNCTIONAL PAIR_POTENTIAL
>>>>     &PAIR_POTENTIAL
>>>>      TYPE DFTD3
>>>>      PARAMETER_FILE_NAME ../../dftd3.dat
>>>>      REFERENCE_FUNCTIONAL PBE
>>>>      CALCULATE_C9_TERM TRUE
>>>>      REFERENCE_C9_TERM TRUE
>>>>      LONG_RANGE_CORRECTION TRUE
>>>>      VERBOSE_OUTPUT TRUE
>>>>      R_CUTOFF 15.0
>>>>     &END PAIR_POTENTIAL
>>>>    &END VDW_POTENTIAL
>>>>   &END XC
>>>>  &END DFT
>>>>
>>>>  &SUBSYS
>>>>   &CELL
>>>>    ABC 16.0 16.0 16.0
>>>>    PERIODIC XYZ
>>>>   &END CELL
>>>>      &TOPOLOGY
>>>>       COORDINATE XYZ
>>>>       COORD_FILE_NAME ../structure
>>>>       CONNECTIVITY OFF
>>>>    # &TOPOLOGY
>>>>     #  COORDINATE XYZ
>>>>       #COORD_FILE_NAME Fin-struct.xyz 
>>>>      # CONNECTIVITY OFF
>>>>     &END TOPOLOGY
>>>>  &END SUBSYS
>>>> &END FORCE_EVAL
>>>>
>>>>          
>>>>    
>>>>
>>>> On Monday, April 23, 2018 at 10:41:00 PM UTC+2, Matt W wrote:
>>>>>
>>>>> Sorry, I posted too quickly without really looking at your setup.
>>>>>
>>>>> The big problem for you is the XC_GRID settings. 
>>>>>
>>>>>    &XC_GRID
>>>>>     XC_SMOOTH_RHO NN50
>>>>>     XC_DERIV NN50_SMOOTH
>>>>>    &END XC_GRID
>>>>>
>>>>> You really do not want to be using heavy smoothing, especially for 
>>>>> this purpose. These settings (see original paper) help get reasonable 
>>>>> forces with a rather low cutoff, but as you increase the cutoff lead to you 
>>>>> continuously redefining the XC functional you use (you are smoothing over 
>>>>> different areas of real space), so they do not converge.
>>>>>
>>>>> Try changing to the defaults
>>>>>
>>>>>    &XC_GRID
>>>>>     XC_SMOOTH_RHO NONE
>>>>>     XC_DERIV PW
>>>>>    &END XC_GRID
>>>>>
>>>>> you should see at least a significant improvement.
>>>>>
>>>>> Matt
>>>>>
>>>>> On Monday, April 23, 2018 at 6:38:35 PM UTC+1, simin pahlavi wrote:
>>>>>>
>>>>>> Also for ngrid 1 the output is:
>>>>>> shouldn't we not see any changes less than 10e-7 in energy with 
>>>>>> changing cutoff?
>>>>>> I relay appreciate any help here
>>>>>>
>>>>>>   50.0000000000  -230.3665655634           0
>>>>>>  100.0000000000  -231.5201721491          0
>>>>>>  150.0000000000  -231.6333696011           0
>>>>>>  200.0000000000 -231.6954662742           0
>>>>>>  250.0000000000  -231.7211472374          0
>>>>>>  300.0000000000  -231.7441677975          0
>>>>>>  350.0000000000 -231.7546966069           0
>>>>>>  400.0000000000  -231.7608341845          0
>>>>>>  450.0000000000  -231.7712553463           0
>>>>>>  500.0000000000  -231.7712553463           0
>>>>>>  550.0000000000  -231.7762288308           0
>>>>>>  600.0000000000  -231.7833659880            0
>>>>>>
>>>>>> On Monday, April 23, 2018 at 6:55:33 PM UTC+2, simin pahlavi wrote:
>>>>>>>
>>>>>>>
>>>>>>> Dear Matteu,
>>>>>>> Thank you very much for your quick answer,
>>>>>>> I am not sure what did you mean by " Your set up is converged at the 
>>>>>>> lowest setting you report",
>>>>>>>  because after first few step with convergence I had a different 
>>>>>>> energy in next cutoffs. 
>>>>>>> but the result for lower cutoff is  as the following.
>>>>>>> Can I ask where is the suitable cutoff is now? and why you say so?
>>>>>>>
>>>>>>>  Grid cutoff vs total energy
>>>>>>> # Date: Mon Apr 23 18:44:42 CEST 2018
>>>>>>> # REL_CUTOFF = 60
>>>>>>> # Cutoff (Ry) | Total Energy (Ha) | NG on grid 1 | NG on grid 2 | NG 
>>>>>>> on grid 3 | NG on grid 4
>>>>>>>   50.0                   -230.3665656028      88679   13322      48  
>>>>>>>      0
>>>>>>>  100.0                  -231.5201721496       69162   25725    7162  
>>>>>>>      0
>>>>>>>  150.0                   231.6333696411       66211   22468   13322  
>>>>>>>     48
>>>>>>>  200.0                  -231.6954662441       48271   28520   25210  
>>>>>>>     48
>>>>>>>  250.0                  -231.7211472373       45554   27891   28476  
>>>>>>>    128
>>>>>>>  300.0                  -231.7441677949       43072   26090   25725  
>>>>>>>   7162
>>>>>>>  350.0                  -231.7546966111       43072   23982   22834  
>>>>>>>  12161
>>>>>>>  400.0                   -231.7608341848      40587   25752   23501  
>>>>>>>  12209
>>>>>>>  450.0                   -231.7712553838       36594   29617  
>>>>>>>  22468   13370
>>>>>>>  500.0                   -231.7712553419        31682   21399  
>>>>>>>  35598   13370
>>>>>>>  550.0                   -231.7762288293       24651   26716  
>>>>>>>  28756   21926
>>>>>>>  600.0                   -231.7833659579        24651   23620  
>>>>>>>  28520   25258
>>>>>>>
>>>>>>> with best regards
>>>>>>> Simin
>>>>>>>
>>>>>>> On Monday, April 23, 2018 at 2:57:15 PM UTC+2, Matt W wrote:
>>>>>>>>
>>>>>>>> To see really clean convergence you need to turn off multigrids 
>>>>>>>> (set ngrids 1).
>>>>>>>>
>>>>>>>> Your set up is converged at the lowest setting you report.
>>>>>>>>
>>>>>>>> We need a new tutorial on how to get happy pw settings.
>>>>>>>>
>>>>>>>> On Monday, April 23, 2018 at 11:38:03 AM UTC+1, simin pahlavi wrote:
>>>>>>>>>
>>>>>>>>> Dear aal,
>>>>>>>>> Hello. 
>>>>>>>>> I am trying to find a suitable cutoff for my DFT calculation on 
>>>>>>>>> hydrocarbons according to the cp2k manual 
>>>>>>>>> https://www.cp2k.org/howto:converging_cutoff. I appriciate any 
>>>>>>>>> help in advance.
>>>>>>>>> The results never converge  and the calculated output for  
>>>>>>>>> REL_CUTOFF = 60, is as following:
>>>>>>>>>   
>>>>>>>>> # Grid cutoff vs total energy
>>>>>>>>> # Date: Fri Apr 20 20:39:04 CEST 2018
>>>>>>>>> # REL_CUTOFF = 60
>>>>>>>>> # Cutoff (Ry) | Total Energy (Ha) | NG on grid 1 | NG on grid 2 | 
>>>>>>>>> NG on grid 3 | NG on grid 4
>>>>>>>>>  800.0                   -231.7994673423      73445   28476    
>>>>>>>>>  128       0
>>>>>>>>>  850.0                   -231.7994673423       73445   28476    
>>>>>>>>>  128       0
>>>>>>>>>  900.0                   -231.8023753152       69162   25725    
>>>>>>>>> 7162       0
>>>>>>>>>  950.0                   -231.8023753152       69162   25725    
>>>>>>>>> 7162       0
>>>>>>>>> 1000.0                  -231.8065368280       69162   25725    
>>>>>>>>> 7162       0
>>>>>>>>> 1050.0                  -231.8065368280       69162   25725    
>>>>>>>>> 7162       0
>>>>>>>>> 1100.0                  -231.8065368280       67054   27833    
>>>>>>>>> 7162       0
>>>>>>>>> 1150.0                  -231.8129239556        67054   22834  
>>>>>>>>>  12161       0
>>>>>>>>> 1200.0                  -231.8129239556        67054   22834  
>>>>>>>>>  12161       0
>>>>>>>>> 1250.0                  -231.8129239556        67054   22834  
>>>>>>>>>  12161       0
>>>>>>>>> 1300.0                  -231.8129239556        66339   23501  
>>>>>>>>>  12209       0
>>>>>>>>> 1350.0                  -231.8129239556        66339   23501  
>>>>>>>>>  12161      48
>>>>>>>>> 1400.0                  -231.8148206637        66259   22420  
>>>>>>>>>  13322      48
>>>>>>>>> 1450.0                  -231.8148206637       66211   22468  
>>>>>>>>>  13322      48
>>>>>>>>> 1500.0                  -231.8148206637        66211   22468  
>>>>>>>>>  13322      48
>>>>>>>>> 1550.0                  -231.8158559068        63323   25356  
>>>>>>>>>  13322      48
>>>>>>>>> 1600.0                  -231.8175292623        57217   31462  
>>>>>>>>>  13322      48
>>>>>>>>>
>>>>>>>>> ********************************************************************************
>>>>>>>>> Also my input file is :
>>>>>>>>>
>>>>>>>>> ******************************************************************************
>>>>>>>>> &GLOBAL
>>>>>>>>>  PRINT_LEVEL MEDIUM
>>>>>>>>> # WALLTIME 36:00:00  # changed
>>>>>>>>>  PROJECT cuttoff-test
>>>>>>>>>  RUN_TYPE ENERGY
>>>>>>>>>  SEED 300
>>>>>>>>> &END GLOBAL
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> &FORCE_EVAL
>>>>>>>>>  METHOD Quickstep
>>>>>>>>>  &DFT
>>>>>>>>>   BASIS_SET_FILE_NAME ../data/BASIS_MOLOPT
>>>>>>>>>   POTENTIAL_FILE_NAME ../data/GTH_POTENTIALS
>>>>>>>>>     CHARGE 0
>>>>>>>>>     MULTIPLICITY 1
>>>>>>>>>     &MGRID
>>>>>>>>>   NGRIDS 4
>>>>>>>>>   CUTOFF LT_cutoff
>>>>>>>>>   REL_CUTOFF LT_rel_cutoff
>>>>>>>>>     &END
>>>>>>>>>    &QS
>>>>>>>>>       EPS_DEFAULT 1.0E-10
>>>>>>>>>       WF_INTERPOLATION PS
>>>>>>>>>       EXTRAPOLATION_ORDER 3
>>>>>>>>>       METHOD GPW
>>>>>>>>>     &END
>>>>>>>>>
>>>>>>>>>   &SCF
>>>>>>>>>    SCF_GUESS ATOMIC
>>>>>>>>>    EPS_SCF 5.e-7
>>>>>>>>>    MAX_SCF 1
>>>>>>>>>       &OT
>>>>>>>>>         MINIMIZER DIIS
>>>>>>>>>       &END OT
>>>>>>>>>    &OUTER_SCF
>>>>>>>>>     TYPE NONE
>>>>>>>>>     OPTIMIZER NONE
>>>>>>>>>     EPS_SCF 5.0E-7  
>>>>>>>>>     MAX_SCF 1
>>>>>>>>>    &END OUTER_SCF 
>>>>>>>>>   &END SCF
>>>>>>>>>
>>>>>>>>>   &XC
>>>>>>>>>    &XC_FUNCTIONAL PBE
>>>>>>>>>    &END XC_FUNCTIONAL
>>>>>>>>>    &XC_GRID
>>>>>>>>>     XC_SMOOTH_RHO NN50
>>>>>>>>>     XC_DERIV NN50_SMOOTH
>>>>>>>>>    &END XC_GRID
>>>>>>>>>    &VDW_POTENTIAL 
>>>>>>>>>     DISPERSION_FUNCTIONAL PAIR_POTENTIAL
>>>>>>>>>     &PAIR_POTENTIAL
>>>>>>>>>      TYPE DFTD3
>>>>>>>>>      PARAMETER_FILE_NAME ../data/dftd3.dat
>>>>>>>>>      REFERENCE_FUNCTIONAL PBE
>>>>>>>>>      CALCULATE_C9_TERM TRUE
>>>>>>>>>      REFERENCE_C9_TERM TRUE
>>>>>>>>>      LONG_RANGE_CORRECTION TRUE
>>>>>>>>>      VERBOSE_OUTPUT TRUE
>>>>>>>>>      R_CUTOFF 15.0
>>>>>>>>>     &END PAIR_POTENTIAL 
>>>>>>>>>    &END VDW_POTENTIAL
>>>>>>>>>   &END XC
>>>>>>>>>  &END DFT
>>>>>>>>>
>>>>>>>>>  &SUBSYS
>>>>>>>>>   &CELL
>>>>>>>>>    ABC 16.0 16.0 16.0
>>>>>>>>>    PERIODIC XYZ
>>>>>>>>>   &END CELL
>>>>>>>>>
>>>>>>>>>     &KIND H
>>>>>>>>>       BASIS_SET DZVP-MOLOPT-SR-GTH-q1
>>>>>>>>>       POTENTIAL GTH-PBE-q1
>>>>>>>>>     &END
>>>>>>>>>
>>>>>>>>>     &KIND C
>>>>>>>>>       BASIS_SET DZVP-MOLOPT-SR-GTH-q4
>>>>>>>>>      POTENTIAL GTH-PBE-q4
>>>>>>>>>     &END KIND
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>     &TOPOLOGY
>>>>>>>>>       COORDINATE XYZ
>>>>>>>>>       COORD_FILE_NAME ../data/structure 
>>>>>>>>>       CONNECTIVITY OFF
>>>>>>>>>     &END TOPOLOGY
>>>>>>>>>  &END SUBSYS
>>>>>>>>> &END FORCE_EVAL
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
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