<div><br></div><div>Hi,</div>To satisfy the equipartition theorem, every degree of freedom should have the same average, 1/2KT<div>If the temperature is not the desired one, it is necessary to adjust the gamma better</div><div>It is normal that the fewer the degrees of freedom are, the larger the temperature's fluctuations, though the averages should be the right ones</div><div><br></div><div>Kind regards</div><div>Marcella</div><div><br><br></div><div class="gmail_quote"><div dir="auto" class="gmail_attr">On Monday, June 27, 2022 at 2:26:00 PM UTC+2 a.celi...@gmail.com wrote:<br/></div><blockquote class="gmail_quote" style="margin: 0 0 0 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><div>Dear Marcella,</div><div>thanks for your answer!</div><div>In my case <Ekin> = 5.3 eV and 3/2*N*kB*T = 4.6eV, is 0.7 eV too much difference? <br></div><div>My target Temperature is 330 K, and the <T> from the calculation is roughly 380 K. In the attached file the temperature of the region are plotted, region of water molecules (32H2O) and region of the first layer Pt atoms (12Pt). Only first layer is allowed to moved.</div><div>What I dont get is why the region of Pt atoms is oscillating a lot?</div><div><br></div><div>BTW energy plots are in Hartree units.<br></div><div><br></div><div>Best regards,<br></div><div><br></div><div><br></div><div> <br></div><br><div class="gmail_quote"><div dir="auto" class="gmail_attr">El jueves, 23 de junio de 2022 a las 16:07:42 UTC+2, Marcella Iannuzzi escribió:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Dear Alexandra<div><br></div><div>If you properly selected the noisy gamma and the equipartition theorem is satisfied, the generated Langevin dynamics should sample the canonical ensemble.</div><div><br></div><div>Regards</div><div>Marcella<br><br></div><div class="gmail_quote"><div dir="auto" class="gmail_attr">On Tuesday, June 21, 2022 at 12:44:20 PM UTC+2 <a rel="nofollow">a.celi...@gmail.com</a> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>Dear cp2k-users,</div><div>thanks to Marcell's suggestions and to Onofrio:</div><div><br></div><div><div>-Always start sgcpmd from a well converged wfn obtained along a standard BOMD run with diagonalisation and smearing</div><div>- Let the first steps run on many scf iterations if needed, i.e., set MAX_SCF large enough</div><div>- But use a relative large eps_scf. The wfn is not going to be optimised as in the BOMD, energy convergence around 10^-5 is desirable</div><div>- Use FULL_ALL preconditioner + ASPC</div><div>- Use a small time step</div><div>- Tune properly GAMMA and NOISY_GAMMA</div></div><div><br></div><div>Now my calculations are converging! Thanks a lot! Per MD step roughly 5 iterations.<br></div><div>My system is water/Pt(111), therefore I used the GAMMA and NOISY_GAMMA from Lan, Jinggang, Jürg Hutter, and Marcella Iannuzzi. "First-principles simulations of an aqueous CO/Pt (111) interface." <i>The Journal of Physical Chemistry C</i> 122.42 (2018): 24068-24076.</div><div><br></div><div>My question is regarding the cons. Q. In ENSEMBLE NVT the cons. Q is equal to the total energy of my system plus energy of thermostat. The energy of the thermostat can be also printed (for only NVT ENSEMBLE) and I was able to verify it. In ENSEMBLE LANGEVIN, which is also at constant temperature, the cons. Q is equal to the total energy of my system. Is that correct? <br></div><div>Maybe I am missing something, because I would interpret it as my system is NVE instead of NVT. Can anybody enlighten me, please?</div><div><br></div><div>I attached the plots of the energies (Hartree units), E_T = cons. Q - Ek - Ep in case of Langevin and NVT ensemble. I know that is a very short simulations but it is just for getting some understanding.</div><div><br></div><div>Many thanks in advance,</div><div>Alexandra<br><em></em></div></blockquote></div></blockquote></div></blockquote></div> <p></p> -- <br /> You received this message because you are subscribed to the Google Groups "cp2k" group.<br /> To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>.<br /> To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/efaed464-c2f1-4967-b020-ff8fcdd5fbafn%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/efaed464-c2f1-4967-b020-ff8fcdd5fbafn%40googlegroups.com</a>.<br />