[CP2K:2396] Pseudooptimization?

Teodoro Laino teodor... at gmail.com
Tue Nov 17 17:22:33 UTC 2009


Centering coordinates after each restart is slightly moving your system. 
This creates spurious forces (because of the presence  of the grid -> 
see old messages) and the optimization may go on over forever..

Take out the CENTER_COORDINATES and everything should go in the way you 
think it should.
Teo

Ilya wrote:
> Dear CP2K users.
>
> I run into a problem few days ago.
>
> I have performed a small (60 atoms) piece of hydrated quartz QS DFT
> relaxation.
>
> Cp2k could not find energy minimum at a time.
>
> If I take optimized coordinates, put them in the input file again and
> restart the optimization with the SCF_GUESS ATOMIC, cp2k will continue
> optimization and will find some lower minimum.
>
> The amount of opt steps needed to reach the minimum is much fewer. The
> energy may differ by ~0.01 but in my case it really matters.
>
> Launching 2-3 sequential optimizations I managed to find the exact
> minimum value.
>
> Anyway it looks suspicious. As it makes up a new wave function
> approximation for an "optimized" coords the whole optimization goes in
> a slightly different way each restart. As I got.
>
> I tried to apply different optmizers - CG, BFGS, LBFGS. I also tried
> to use OT, Mixing/Diag, changing SCF optimizers CG, DIIS. All those
> influenced slightly. Still it does new optimization each restart,
> instead of saing "nothing to do everything is optimized".
>
> Now trying to change CUTOFF value, may be this could help.
> The question might be stupid, I feel that the answer is simple, just
> can't get it.
>
> If someone have some ideas, I will appreciate you advice.
>
> Input
>
>
>  &GLOBAL
>    PRINT_LEVEL  LOW
>    PROJECT_NAME ps-t-11
>    RUN_TYPE  GEO_OPT
>    PREFERRED_FFT_LIBRARY FFTW
>  &END GLOBAL
>  &MOTION
>    &GEO_OPT
>      OPTIMIZER  CG
>      MAX_DR 3.00000000E-04
>      MAX_FORCE  4.50000000E-05
>      RMS_DR    1.50000000E-04
>      RMS_FORCE  3.00000000E-05
>      MAX_ITER             1000
>    &END GEO_OPT
>  &END MOTION
>  &FORCE_EVAL
>    METHOD  QS
>    &DFT
>      BASIS_SET_FILE_NAME GTH_BASIS_SETS
>      &SCF
>        SCF_GUESS ATOMIC
>        MAX_SCF            1000
>      &END SCF
>      &XC
>        &XC_FUNCTIONAL  PBE
>        &END XC_FUNCTIONAL
>      &END XC
>      &POISSON
>        PERIODIC XZ
>        POISSON_SOLVER WAVELET
>      &END POISSON
>    &END DFT
>    &SUBSYS
>      &CELL
>       ABC     9.8724 25.0 10.08094
>     UNITS  ANGSTROM
>        PERIODIC  XZ
>      &END CELL
>      &KIND Si
>        BASIS_SET TZVP-GTH
>        POTENTIAL GTH-PBE-q4
>      &END KIND
>      &KIND O
>        BASIS_SET TZVP-GTH
>        POTENTIAL GTH-PBE-q6
>      &END KIND
>      &KIND C
>        BASIS_SET TZVP-GTH
>        POTENTIAL GTH-PBE-q4
>      &END KIND
>      &KIND B
>        BASIS_SET TZVPP-GTH
>        POTENTIAL GTH-PBE-q3
>      &END KIND
>      &KIND H
>        BASIS_SET TZVP-GTH
>        POTENTIAL GTH-PBE-q1
>      &END KIND
>      &TOPOLOGY
>        COORD_FILE_FORMAT XYZ
>        COORD_FILE_NAME /home/kupchenko/job/ps/t/ps.xyz
>        CENTER_COORDINATES  T
>      &END TOPOLOGY
>    &END SUBSYS
>  &END FORCE_EVAL
>
> Coordinate file ps.xyz:
>
>       60
>  i =        1, E =      -570.7446060489
>   H         1.2164405235       15.4842136302        0.4143744831
>   H         6.1121896899       15.5038087647        0.4144334876
>   H         1.2707602262       15.3655789278        5.4048093021
>   H         6.1271079554       15.4026946050        5.4235580700
>   O         0.4551586659       15.1183862048        0.9207263709
>   O         5.3651001781       15.1154121407        0.9229189539
>   O         0.5077183637       15.1235599574        5.9915222988
>   O         5.3762635138       15.1158339064        6.0005346429
>   H         3.8570937184       15.1545145022        5.1023747623
>   H         8.8344418767       15.1584752804        5.0833260666
>   H         3.8786236331       15.1947700953       10.3189982581
>   H         8.8423420430       15.2102731172       10.2764809174
>   O         3.0957286169       14.9472184410        4.5045744980
>   O         8.0582595943       14.9554451515        4.5037182386
>   O         3.0983543419       14.9962628173        9.7165567981
>   O         8.0637432247       15.0292909929        9.6668423665
>   O         2.4682398721       13.9468761359        2.1126453081
>   O         7.4016859412       13.9535260868        2.1076981879
>   O         2.4331459358       13.9452444285        7.4094370497
>   O         7.3474209604       13.9487720010        7.3996943622
>  Si         0.9174823157       13.6452453328        1.6331964708
>  Si         5.8506776815       13.6460140438        1.6312922823
>  Si         0.8945731285       13.7654223514        6.8801727781
>  Si         5.8090768385       13.7639843442        6.8815442106
>  Si         3.3445442865       13.6624717732        3.4584593898
>  Si         8.2735277184       13.6625861281        3.4589630814
>  Si         3.3211393429       13.6848373669        8.7566224332
>  Si         8.2481557358       13.6840992310        8.7402594584
>   O         4.9261822520       13.4850120463        3.0058435744
>   O         9.8492612051       13.4823424700        2.9989183455
>   O         4.8578563490       13.4964580997        8.1955274091
>   O         9.7798690555       13.4911169759        8.1692673736
>   O         0.8797033120       12.3830946804        0.6001141356
>   O         5.7933420692       12.3831395817        0.6001632671
>   O         0.8817757579       12.3795984391        6.0019735587
>   O         5.7953154313       12.3796068132        6.0019844251
>   O         2.7873912363       12.2645536217        4.1156930416
>   O         7.7011498729       12.2647096129        4.1156209075
>   O         2.8124720845       12.2891736146        9.5066763280
>   O         7.7263380707       12.2894528459        9.5065558302
>  Si         1.8767330997       11.4234259421       -0.2249206571
>  Si         6.7904244881       11.4233716970       -0.2249530592
>  Si         1.8906925923       11.4346717365        5.1661113227
>  Si         6.8044045172       11.4346717256        5.1660918387
>   O         2.8683800441       10.6886833092        0.8130047883
>   O         7.7820554561       10.6886976079        0.8130092380
>   O         2.8661225434       10.6907181430        6.2154513092
>   O         7.7798155302       10.6907252061        6.2154563221
>   O         0.9993480464       10.3826593668        4.3304611630
>   O         5.9130553067       10.3826768100        4.3304808739
>   O         0.9879650764       10.3694140533        9.7308331231
>   O         5.9016086863       10.3694428080        9.7308465605
>   H         2.5220936594        9.9015909978        1.2556566675
>   H         7.4361354814        9.8984291273        1.2500346062
>   H         3.8152371223       10.6874649056        5.9934984006
>   H         8.7297691935       10.6932243995        5.9965260796
>   H         1.3674986990        9.4962228514        4.1919909263
>   H         6.2998681174        9.5107427878        4.1552631113
>   H         0.0234329886       10.3965414804        9.7770309728
>   H         4.9370093473       10.3979787214        9.7924189287
>
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