[CP2K-user] [CP2K:14614] Re: Struggling to get SCF Convergence in Cell_Opt run
Lenard Carroll
lenardc... at gmail.com
Fri Jan 22 08:18:46 UTC 2021
Then I cannot use smearing, I guess I'll have to turn it off or will have
to talk to my supervisor about using a non-zero temperature.
On Fri, Jan 22, 2021 at 10:17 AM Marcella Iannuzzi <marci... at gmail.com>
wrote:
>
>
> No smearing with 0K does not help.
> Smearing needs a finite temperature, can be lower than 500, for instance
> 300K, not 0K
> On Friday, January 22, 2021 at 9:04:31 AM UTC+1 ASSIDUO Network wrote:
>
>> I'm going to follow your advice, but if I remember correctly, last time I
>> tried smearing with 0 K, the stimulation ended with an error. If it does it
>> again, I will ask for some feedback again.
>>
>> On Friday, January 22, 2021 at 9:59:40 AM UTC+2 Marcella Iannuzzi wrote:
>>
>>>
>>>
>>> Hi
>>>
>>> The smearing with finite electronic temperature is needed in order to
>>> allow convergence of the metallic electronic structure, even if the
>>> structure is kept a 0K. The number of added MOS depends on the density of
>>> states around Fermi. Too many states do not hurt, in terms of convergence.
>>> I just chose a safe number, probably less are also OK, as a lower smearing
>>> temperature would also work.
>>> As a functional I took one that I often use. Anyway, I think that adding
>>> VDW is a good idea.
>>> All these aspects are more general on electronic structure theory and
>>> not specific of CP2K. Please read in the literature for better
>>> understanding.
>>> Regards
>>> Marcella
>>>
>>>
>>> On Friday, January 22, 2021 at 8:37:46 AM UTC+1 ASSIDUO Network wrote:
>>>
>>>> I should have added this earlier, the simulation must be performed at 0
>>>> K (my supervisor's request), it's a static run. Therefore, I cannot set the
>>>> temperature to 500 K. Also, why the need for ADDED_MOS=200? In another
>>>> thread, I was told that ADDED_MOS=100 was too much.
>>>>
>>>> Also, why the use of FUNCTIONAL XC_GGA_C_PBE and FUNCTIONAL
>>>> XC_GGA_X_RPW86? I'm new to CP2K so just want to understand everything
>>>> better.
>>>> On Friday, January 22, 2021 at 9:24:10 AM UTC+2 Marcella Iannuzzi wrote:
>>>>
>>>>> Hi Lenard,
>>>>>
>>>>> I got it converging in 10 iterations.
>>>>> The outer SCF with diagonalisation is useless, since there is no
>>>>> preconditioner.
>>>>> With metals you need to use smearing.
>>>>> Here are some settings I used:
>>>>> ADDED_MOS 200
>>>>> &DIAGONALIZATION T
>>>>> ALGORITHM STANDARD
>>>>> &END DIAGONALIZATION
>>>>> &MIXING T
>>>>> METHOD BROYDEN_MIXING
>>>>> ALPHA 0.01
>>>>> BETA 0.5
>>>>> NBUFFER 8
>>>>> &END MIXING
>>>>> &SMEAR
>>>>> METHOD FERMI_DIRAC
>>>>> ELECTRONIC_TEMPERATURE 500
>>>>> &END SMEAR
>>>>>
>>>>> &XC
>>>>> &XC_FUNCTIONAL
>>>>> &LIBXC
>>>>> FUNCTIONAL XC_GGA_X_RPW86
>>>>> &END LIBXC
>>>>> &LIBXC
>>>>> FUNCTIONAL XC_GGA_C_PBE
>>>>> &END LIBXC
>>>>> &END XC_FUNCTIONAL
>>>>>
>>>>> &VDW_POTENTIAL
>>>>> POTENTIAL_TYPE NON_LOCAL
>>>>> &NON_LOCAL
>>>>> CUTOFF 300
>>>>> TYPE RVV10
>>>>> ## VERBOSE_OUTPUT
>>>>> KERNEL_FILE_NAME ${data}/rVV10_kernel_table.dat
>>>>> &END NON_LOCAL
>>>>> &END VDW_POTENTIAL
>>>>> &END XC
>>>>>
>>>>> The results:
>>>>>
>>>>> Step Update method Time Convergence Total energy
>>>>> Change
>>>>>
>>>>> ------------------------------------------------------------------------------
>>>>> 1 NoMix/Diag. 0.10E-01 20.0 0.51067755 -133.2796876462
>>>>> -1.33E+02
>>>>> 2 Broy./Diag. 0.10E-01 17.6 0.00064724 -136.0334243526
>>>>> -2.75E+00
>>>>> 3 Broy./Diag. 0.10E-01 17.5 0.03257808 -134.7316158415
>>>>> 1.30E+00
>>>>> 4 Broy./Diag. 0.10E-01 17.7 0.00019866 -133.0666478987
>>>>> 1.66E+00
>>>>> 5 Broy./Diag. 0.10E-01 17.6 0.00228816 -133.1462861174
>>>>> -7.96E-02
>>>>> 6 Broy./Diag. 0.10E-01 17.6 0.00032933 -133.1654553845
>>>>> -1.92E-02
>>>>> 7 Broy./Diag. 0.10E-01 17.6 0.00000406 -133.1816175525
>>>>> -1.62E-02
>>>>> 8 Broy./Diag. 0.10E-01 17.7 0.00009047 -133.1825852315
>>>>> -9.68E-04
>>>>> 9 Broy./Diag. 0.10E-01 17.6 0.00000504 -133.1830490186
>>>>> -4.64E-04
>>>>> 10 Broy./Diag. 0.10E-01 17.6 0.00000031 -133.1828944498
>>>>> 1.55E-04
>>>>>
>>>>> *** SCF run converged in 10 steps ***
>>>>>
>>>>>
>>>>> Electronic density on regular grids: -44.0000000000
>>>>> 0.0000000000
>>>>> Core density on regular grids: 43.9999999999
>>>>> -0.0000000001
>>>>> Total charge density on r-space grids: -0.0000000001
>>>>> Total charge density g-space grids: -0.0000000001
>>>>>
>>>>> Overlap energy of the core charge distribution:
>>>>> 0.00000001219968
>>>>> Self energy of the core charge distribution:
>>>>> -231.41335460772382
>>>>> Core Hamiltonian energy:
>>>>> 74.19344628639691
>>>>> Hartree energy:
>>>>> 45.27318657026385
>>>>> Exchange-correlation energy:
>>>>> -21.30000506759340
>>>>> Dispersion energy:
>>>>> 0.06400174824714
>>>>> Electronic entropic energy:
>>>>> -0.00016939092888
>>>>> Fermi energy:
>>>>> 0.34714684334798
>>>>>
>>>>> Total energy:
>>>>> -133.18289444982969
>>>>>
>>>>>
>>>>>
>>>>> Regards
>>>>> Marcella
>>>>>
>>>>> On Friday, January 22, 2021 at 6:48:12 AM UTC+1 ASSIDUO Network wrote:
>>>>>
>>>>>> Hi there everyone, hope you've had a great week.
>>>>>>
>>>>>> I've been trying to run a cell optimization of bulk Au, and I am
>>>>>> using the attached input file, but I'm not getting an inner loop SCF
>>>>>> convergence. I've made many small changes, such as including/excluding
>>>>>> OUTER_SCF, changing the SCF convergence criterion, changing the number of
>>>>>> cell optimization steps, changing the number of KPoints and changing the
>>>>>> mixing method. Nothing has worked. I haven't tried a combination of the
>>>>>> above though.
>>>>>>
>>>>>> Do you perhaps have any suggestions to me on how to get convergence?
>>>>>> Furthermore, I would also appreciate some tips to speed up my simulations
>>>>>> (settings/flags) wise.
>>>>>>
>>>>>> Thanks in advance,
>>>>>> Lenard
>>>>>>
>>>>>>
>>>>>> --
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