[CP2K:4024] Energy conservation NVT/NVE simulation

alber... at virgilio.it alber... at virgilio.it
Tue Sep 11 09:35:42 UTC 2012


Hi,

for the restart I used the last restart file of the previous run, modifying 
the parameters in $QS or $SCF to test the new ones.
I observed a drift also for NVE even if most of the tests have been done 
for NVT.
I will carry out more tests for NVE to reduce the number of variables and 
avoid also the problem of thermostat setting.

About the drift, after few ps it is about 10^-3 au, depending on the 
simulations. 
Changing the parameters to increase the accuracy, in some cases I observed 
no drift but sudden jumps in the total energy.

I will keep you updated about further NVE tests.
Thanks

alberto

Il giorno martedì 11 settembre 2012 11:04:00 UTC+2, jgh ha scritto:
>
> Hi 
>
> it is difficult to give good advice without more information. 
>
> Possible problems might be: 
>
> - Restarts: do you correctly restart all variables 
> - Thermostat: I don't know if the setting you have is reasonable 
>               and adequate for this timestep. 
>               Do you see a drift also for NVE? 
> - How big is the drift and how long is your trajectory? 
>
> regards 
>
> Juerg 
>
> -------------------------------------------------------------- 
> Juerg Hutter                         Phone : ++41 44 635 4491 
> Physical Chemistry Institute   FAX   : ++41 44 635 6838 
> University of Zurich               E-mail:  hut... at pci.uzh.ch<javascript:> 
> Winterthurerstrasse 190 
> CH-8057 Zurich, Switzerland 
> --------------------------------------------------------------- 
>
> -----cp... at googlegroups.com <javascript:> wrote: ----- 
> To: cp... at googlegroups.com <javascript:> 
> From: "albe... at virgilio.it <javascript:>" 
> Sent by: cp... at googlegroups.com <javascript:> 
> Date: 09/11/2012 10:06AM 
> Subject: Re: [CP2K:4024] Energy conservation NVT/NVE simulation 
>
> Dear Juerg, 
>
> thank you very much. 
>
> I changed the functional to BLYP and I used ASPC interpolator. 
> I carried out different tests where I tried different values of the 
> EXTRAPOLATION_ORDER (up to 6), I increased the EPS_SCF and used defaults 
> for most of the other parameters. 
> Unfortunately, I still observe either drifts or jumps in the total energy. 
>
> I think that there is still a problem in the input, reported below. 
>
> Many thanks for your help. 
>
> Alberto  
>
> ************ 
>
> &FORCE_EVAL 
>   METHOD QS 
>   &DFT 
>     BASIS_SET_FILE_NAME GTH_BASIS_SETS 
>     POTENTIAL_FILE_NAME GTH_POTENTIALS 
>     &MGRID 
>       CUTOFF 300 
>       REL_CUTOFF 40 
>     &END MGRID 
>     &QS 
>       EPS_DEFAULT 1.0E-12 
>       WF_INTERPOLATION ASPC 
>       EXTRAPOLATION_ORDER 3 
>     &END QS 
>     &SCF 
>       SCF_GUESS ATOMIC 
>       EPS_SCF 1.0E-6 
>       &OT T 
>       &END OT 
>       &PRINT 
>         &RESTART OFF 
>         &END 
>       &END 
>     &END SCF 
>     &XC 
>       &XC_FUNCTIONAL BLYP 
>       &END XC_FUNCTIONAL 
>     &END XC 
>     &PRINT 
>       &MOMENTS MEDIUM 
>       &END 
>     &END PRINT 
>   &END DFT 
>   &SUBSYS 
>     &CELL 
>       ABC 9.8528 9.8528 9.8528 
>     &END CELL 
>     # 32 H2O (TIP5P,1bar,300K) a = 9.8528 
>     &COORD 
>    O       2.280398       9.146539       5.088696 
>    O       1.251703       2.406261       7.769908 
>    O       1.596302       6.920128       0.656695 
>    O       2.957518       3.771868       1.877387 
>    O       0.228972       5.884026       6.532308 
>    O       9.023431       6.119654       0.092451 
>    O       7.256289       8.493641       5.772041 
>    O       5.090422       9.467016       0.743177 
>    O       6.330888       7.363471       3.747750 
>    O       7.763819       8.349367       9.279457 
>    O       8.280798       3.837153       5.799282 
>    O       8.878250       2.025797       1.664102 
>    O       9.160372       0.285100       6.871004 
>    O       4.962043       4.134437       0.173376 
>    O       2.802896       8.690383       2.435952 
>    O       9.123223       3.549232       8.876721 
>    O       1.453702       1.402538       2.358278 
>    O       6.536550       1.146790       7.609732 
>    O       2.766709       0.881503       9.544263 
>    O       0.856426       2.075964       5.010625 
>    O       6.386036       1.918950       0.242690 
>    O       2.733023       4.452756       5.850203 
>    O       4.600039       9.254314       6.575944 
>    O       3.665373       6.210561       3.158420 
>    O       3.371648       6.925594       7.476036 
>    O       5.287920       3.270653       6.155080 
>    O       5.225237       6.959594       9.582991 
>    O       0.846293       5.595877       3.820630 
>    O       9.785620       8.164617       3.657879 
>    O       8.509982       4.430362       2.679946 
>    O       1.337625       8.580920       8.272484 
>    O       8.054437       9.221335       1.991376 
>    H       1.762019       9.820429       5.528454 
>    H       3.095987       9.107088       5.588186 
>    H       0.554129       2.982634       8.082024 
>    H       1.771257       2.954779       7.182181 
>    H       2.112148       6.126321       0.798136 
>    H       1.776389       7.463264       1.424030 
>    H       3.754249       3.824017       1.349436 
>    H       3.010580       4.524142       2.466878 
>    H       0.939475       5.243834       6.571945 
>    H       0.515723       6.520548       5.877445 
>    H       9.852960       6.490366       0.393593 
>    H       8.556008       6.860063      -0.294256 
>    H       7.886607       7.941321       6.234506 
>    H       7.793855       9.141028       5.315813 
>    H       4.467366       9.971162       0.219851 
>    H       5.758685      10.102795       0.998994 
>    H       6.652693       7.917443       3.036562 
>    H       6.711966       7.743594       4.539279 
>    H       7.751955       8.745180      10.150905 
>    H       7.829208       9.092212       8.679343 
>    H       8.312540       3.218330       6.528858 
>    H       8.508855       4.680699       6.189990 
>    H       9.742249       1.704975       1.922581 
>    H       8.799060       2.876412       2.095861 
>    H       9.505360       1.161677       6.701213 
>    H       9.920117      -0.219794       7.161006 
>    H       4.749903       4.186003      -0.758595 
>    H       5.248010       5.018415       0.403676 
>    H       3.576065       9.078451       2.026264 
>    H       2.720238       9.146974       3.273164 
>    H       9.085561       4.493058       9.031660 
>    H       9.215391       3.166305       9.749133 
>    H       1.999705       2.060411       1.927796 
>    H       1.824184       0.564565       2.081195 
>    H       7.430334       0.849764       7.438978 
>    H       6.576029       1.537017       8.482885 
>    H       2.415851       1.576460       8.987338 
>    H       2.276957       0.099537       9.289499 
>    H       1.160987       1.818023       4.140602 
>    H       0.350256       2.874437       4.860741 
>    H       5.768804       2.638450       0.375264 
>    H       7.221823       2.257514       0.563730 
>    H       3.260797       5.243390       5.962382 
>    H       3.347848       3.732214       5.988196 
>    H       5.328688       9.073059       5.982269 
>    H       5.007063       9.672150       7.334875 
>    H       4.566850       6.413356       3.408312 
>    H       3.273115       7.061666       2.963521 
>    H       3.878372       7.435003       6.843607 
>    H       3.884673       6.966316       8.283117 
>    H       5.918240       3.116802       5.451335 
>    H       5.355924       2.495093       6.711958 
>    H       5.071858       7.687254      10.185667 
>    H       6.106394       7.112302       9.241707 
>    H       1.637363       5.184910       4.169264 
>    H       0.427645       4.908936       3.301903 
>    H       9.971698       7.227076       3.709104 
>    H      10.647901       8.579244       3.629806 
>    H       8.046808       5.126383       2.213838 
>    H       7.995317       4.290074       3.474723 
>    H       1.872601       7.864672       7.930401 
>    H       0.837635       8.186808       8.987268 
>    H       8.314696      10.115534       2.212519 
>    H       8.687134       8.667252       2.448452 
>     &END COORD 
>     &KIND H 
>       BASIS_SET TZV2P-GTH 
>       POTENTIAL GTH-BLYP-q1 
>     &END KIND 
>     &KIND O 
>       BASIS_SET TZV2P-GTH 
>       POTENTIAL GTH-BLYP-q6 
>     &END KIND 
>   &END SUBSYS 
> &END FORCE_EVAL 
> &GLOBAL 
>   PROJECT H2O-32 
>   RUN_TYPE MD 
>   PRINT_LEVEL MEDIUM 
>   &TIMINGS 
>      THRESHOLD 0.000001 
>   &END 
> &END GLOBAL 
> &MOTION 
>   &MD 
>     ENSEMBLE NVT 
>     STEPS 30000 
>     TIMESTEP 0.5 
>     TEMPERATURE 300.0 
>     &THERMOSTAT 
>       TYPE CSVR 
>       &CSVR 
>         TIMECON 100.0 
>       &END CSVR 
>     &END THERMOSTAT 
>   &END MD 
>   &PRINT 
>     &VELOCITIES LOW 
>     &END 
>   &END PRINT 
> &END MOTION 
>
> ************** 
>
>
> Il giorno mercoledì 5 settembre 2012 09:56:16 UTC+2, jgh ha scritto:Hi 
>   
> the main problem is 
>   
>      &QS 
>       EPS_DEFAULT 1.0E-12 
>       WF_INTERPOLATION PS 
>       EXTRAPOLATION_ORDER 3 
>     &END QS 
>   
> change to WF_INTERPOLATION ASPC (the default) and maybe 
> increase the EXTRAPOLATION_ORDER slightly. 
> See   
> J. Hutter, Car-Parrinello molecular dynamics 
> Wiley Interdisciplinary Reviews: Computational Molecular Science 2 (4) , 
> pp. 604-612   
> for an explanation. 
>   
> You should also change to a more reasonable DFT functional. 
> LDA (PADE) will lead to an extremly overstructured system. 
> See   
> J. Schmidt et al.,   
> Isobaric-isothermal molecular dynamics simulations utilizing density 
> functional theory: An assessment of the structure and density of water at 
> near-ambient conditions 
> Journal of Physical Chemistry B Volume 113, Issue 35, 3 September 2009, 
> Pages 11959-11964 
>   
> regards 
>   
> Juerg 
>   
> -------------------------------------------------------------- 
> Juerg Hutter                         Phone : ++41 44 635 4491 
> Physical Chemistry Institute   FAX   : ++41 44 635 6838 
> University of Zurich               E-mail:  hut... at pci.uzh.ch 
> Winterthurerstrasse 190 
> CH-8057 Zurich, Switzerland 
> --------------------------------------------------------------- 
>   
> -----cp... at googlegroups.com wrote: ----- 
> To: cp... at googlegroups.com 
> From: "albe... at virgilio.it"   
> Sent by: cp... at googlegroups.com 
> Date: 09/05/2012 09:44AM 
> Subject: [CP2K:4010] Energy conservation NVT/NVE simulation 
>   
> Dear all, 
>   
> I'm carrying out some tests to reproduce the VDOS of water and I used as 
> starting points the input files 'H2O-32.inp' and 'H2O-64.inp' in 
> tests/QS/benchmark directory. 
>   
> In both cases I ran a NVT simulation at 300K for 15 ps followed by an NVE 
> simulation on the equilibrated system. 
>   
> I'm puzzled about the results in the energies: in both NVT and NVE  the 
> plot of 
> "Cons Qty" show a constant and linear drift while temperature, kinetic and 
> potential energy are equilibrated and stable. 
>   
> Since "Cons Qty" should be conserved and this is not the case I think that 
> there are some problems in the setup of the simulation. 
> I did not modify the parameters of the benchmark inputs but I just added 
> the 
> thermostat section in NVT and I modified only the printing option. 
>   
> Thank you very much for your help and suggestions, 
>   
> Alberto 
>   
>     
>   --   
>  You received this message because you are subscribed to the Google Groups 
> "cp2k" group. 
>  To view this discussion on the web visit 
> https://groups.google.com/d/msg/cp2k/-/LgSDjVEpz0YJ. 
>   To post to this group, send email to cp... at googlegroups.com. 
>  To unsubscribe from this group, send email to 
> cp2k+... at googlegroups.com. 
>   For more options, visit this group at 
> http://groups.google.com/group/cp2k?hl=en. 
>       
>   -- 
>  You received this message because you are subscribed to the Google Groups 
> "cp2k" group. 
>  To view this discussion on the web visit 
> https://groups.google.com/d/msg/cp2k/-/yrA7tbiv8B4J. 
>   To post to this group, send email to cp... at googlegroups.com<javascript:>. 
>
>  To unsubscribe from this group, send email to 
> cp2k+... at googlegroups.com <javascript:>. 
>   For more options, visit this group at 
> http://groups.google.com/group/cp2k?hl=en. 
>    

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20120911/ead080f2/attachment.htm>


More information about the CP2K-user mailing list