<div dir="ltr"><div><div><div><div><div><div>Hi Sergey, </div>the Siepmann-Sprik potential assumes intact water molecules at the interface. In your case, some dissociation seems to take place. It is checked with a simple distance criterion if we have 2 hydrogens per oxygen. You get the error message: Error in Siepmann-Sprik part: too many H atoms, i.e. more than 2 hydrogen per oxygen found. </div>The keyword ALLOW_OH_FORMATION ignores that and doesn't calculate the T3 term of the Siepmann-Sprik potential for this MD step. So the program won't stop. This keyword was actually intended for cases where water is described at the QM level, but you can try it as well. </div>It's strange that you have this behavior at the SPC level. However, the temperature development of your MD is very weird and has extreme jumps. So it's maybe not surprising that your O-H bonds are strangely stretched. So better control your MD setup and parameters. </div>btw: examples for the Siepmann-Sprik potential can be found in the regtests: /cp2k/tests/Fist/regtest-6/ </div>Best regards, </div>Dorothea <div><div><div><div><div><div><div> </div></div></div></div></div></div></div></div><div class="gmail_extra"> <div class="gmail_quote">2015-11-12 20:56 GMT+01:00 Sergey Doronin <<a href="mailto:sedo...@gmail.com" target="_blank">sedo...@gmail.com</a>>: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi, dear colleagues Last weeks I started MD calculation of Pt+H2O system. Water was presented by SPC model, Pt-H2O described by Siepmann-Sprik type potential (parameters of potential were taken from J.I. Siepmann and M.Sprik // J.Chem.Phys. Vol. 102, No. 1, 1995). Unfortunately all calculations are terminated as: (file Pt111_1586H2O_Test1) ENERGY| Total FORCE_EVAL ( FIST ) energy (a.u.): -31.736442138935644 Centre of mass motion (COM): x = -0.0000001751 y = 0.0000000386 z = -0.0000002641 ******************************************************************************* ENSEMBLE TYPE = NVT STEP NUMBER = 4210 TIME [fs] = 421.000000 CONSERVED QUANTITY [hartree] = 0.132931078387E+04 INSTANTANEOUS AVERAGES CPU TIME [s] = 0.97 1.01 ENERGY DRIFT PER ATOM [K] = 0.746520229520E+05 0.483172888277E+05 POTENTIAL ENERGY[hartree] = -0.317364421389E+02 -0.305625006633E+02 KINETIC ENERGY [hartree] = 0.294647664771E+01 0.450202835322E+01 TEMPERATURE [K] = 195.611 298.881 ******************************************************************************* MM DIPOLE [BERRY PHASE](A.U.)| -5.474236 -7.277890 -24.581328 MM DIPOLE [BERRY PHASE](Debye)| -13.914119 -18.498550 -62.479498 MM DIPOLE [BERRY PHASE] DERIVATIVE(A.U.)| -0.011981 -0.010334 0.009710 ENERGY| Total FORCE_EVAL ( FIST ) energy (a.u.): 8772.964220420968559 Centre of mass motion (COM): x = -0.0000010184 y = 0.0000002238 z = -0.0000015332 ******************************************************* *** ERROR in siep_Phi_ij (MODULE manybody_siepmann) *** ******************************************************* *** Error in Siepmann-Sprik part: too many H atoms *** *** Program stopped at line number 338 of MODULE manybody_siepmann *** or sometimes (file Pt111_1586H2O_Test2) terminated as Centre of mass motion (COM): x = -0.0000000528 y = -0.0000000109 z = -0.0000001862 MM DIPOLE [BERRY PHASE](A.U.)| -6.717544 2.821496 -3.847367 MM DIPOLE [BERRY PHASE](Debye)| -17.074293 7.171526 -9.779030 MM DIPOLE [BERRY PHASE] DERIVATIVE(A.U.)| -0.002798 -0.008723 0.005970 ENERGY| Total FORCE_EVAL ( FIST ) energy (a.u.): -31.096110069961611 Centre of mass motion (COM): x = -0.0000000505 y = -0.0000000105 z = -0.0000001776 MM DIPOLE [BERRY PHASE](A.U.)| -6.729504 2.834566 -3.852281 MM DIPOLE [BERRY PHASE](Debye)| -17.104691 7.204748 -9.791520 MM DIPOLE [BERRY PHASE] DERIVATIVE(A.U.)| -0.002638 -0.008331 0.005670 ENERGY| Total FORCE_EVAL ( FIST ) energy (a.u.): 96420902.412601232528687 ********************************************************************** ********************************************************************** *** 22:43:43 ERRORL3 in thermostat_utils:communication_thermo_low1 *** *** processor 0 :: err=-300 condition FAILED at line 1877 *** ********************************************************************** ********************************************************************** I’ve varied the basic parameters to solve the problem: time steps, temperature, type and parameters of thermostat, Pt-O potential in &genpot section and etc. But all manipulation doesn’t give anything. Anyway, each task has a jump of energy at last iteration. A network also doesn’t have any information. Can anyone please help me to solve this problem? Maybe someone work with Siepmann potential?</div> -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+uns...@googlegroups.com" target="_blank">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com" target="_blank">cp...@googlegroups.com</a>. Visit this group at <a href="http://groups.google.com/group/cp2k" target="_blank">http://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/d/optout" target="_blank">https://groups.google.com/d/optout</a>. </blockquote></div> </div>