Cut-off problrm
Matt W
mattwa... at gmail.com
Tue May 1 20:11:48 UTC 2018
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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