<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="en-CH" link="blue" vlink="purple" style="word-wrap:break-word"> <div class="WordSection1"> Dear Vittorio<o:p></o:p> <o:p> </o:p> a CP2K input file for 32 TIP3P water molecules is attached.<o:p></o:p> I plan to provide template CP2K inputs for the common 3- and 4-site rigid and flexible water models in the CP2K data folder soon. I will announce that here when done.<o:p></o:p> <o:p> </o:p> HTH<o:p></o:p> <o:p> </o:p> Matthias<o:p></o:p> <o:p> </o:p> <div id="mail-editor-reference-message-container"> <div> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"> From: 'Vittorio Bariosco' via cp2k <cp2k@googlegroups.com> Date: Tuesday, 17 October 2023 at 17:19 To: cp2k <cp2k@googlegroups.com> Subject: [CP2K:19377] Optimizing with TIP3P a water cluster model<o:p></o:p> </div> Dear CP2K users,<o:p></o:p> <div> <o:p> </o:p> </div> <div> I have been through different threads on this forum to understand how to optimize a cluster of 600 hundred atoms (see 0_tip3p_geom.xyz) with TIP3P model.<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> 1)I firstly tried this input taken from the FIST repository on GitHub <a href="https://github.com/cp2k/cp2k/blob/master/tests/Fist/regtest-4/H2O-1.inp"> here</a><o:p></o:p> </div> <div> (see first_tip3p.inp) but I was always getting this error after the Optimization starts:<o:p></o:p> </div> <div> "WARNING| Particles: 600 598 at distance [au]: 1.82837959 less than: 2.00430963; increase EMAX_SPLINE.<o:p></o:p> </div> <div> GEOMETRY wrong or EMAX_SPLINE too small!"<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> <o:p> </o:p> </div> <div> <o:p> </o:p> </div> <div> <o:p> </o:p> </div> <div> 2)The I moved to the other input reported in the same repository at this <a href="https://github.com/cp2k/cp2k/blob/master/tests/Fist/regtest-4/H2O-32_SPME_fp.inp."> link</a>, where more water molecules were included in the initial geometry. In this case (see second_tip3p.inp), the optimization starts but at a certain point it crashes again with a similar error: <o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> "WARNING| Particles: 600 598 at distance [au]: 0.89796367 less than: 0.95400000; increase EMAX_SPLINE."<o:p></o:p> </div> <div> GEOMETRY wrong or EMAX_SPLINE too small! <o:p></o:p> <o:p></o:p> At this point I am a little confused on how to proceed. I remembered that tip3p is a rigid FF and I started to look for constraining options for intramolecular distances and angles. I found in the same input of the above the section &CONSTRAINT &G3X3.<o:p></o:p> <o:p> </o:p> 3) Thus, I defined the new input using this constrain that could probably explains the reason why CP2K was crushing before in this way (see third_tip3p.inp). However, also this test was unsuccessful with the following error:<o:p></o:p> <o:p> </o:p> " | Error in constraints setup!<o:p></o:p> | A constraint has been defined for a molecule type<o:p></o:p> | but the atoms specified in the constraint and the atoms defined for<o:p></o:p> | the molecule DO NOT match!<o:p></o:p> | This could be very probable due to a wrong connectivity, or an error<o:p></o:p> | in the constraint specification in the input file.<o:p></o:p> | Please check it carefully!"<o:p></o:p> <o:p> </o:p> Moreover, I also found in another thread <a href="https://groups.google.com/g/cp2k/c/ld5pmmYUnBk/m/iZte7XZGBwAJ">here</a>, that the specified constrained keyword works only for MD runs and not for GEO_OPT or CELL_OPT. <o:p></o:p> <o:p> </o:p> At the moment I don't have any clue in how to proceed to obtain a optimized geometry with tip3p model. For this reason I would like to ask if anybody have ever optimized with tip3p model, or can help me for setting the proper input.<o:p></o:p> <o:p> </o:p> Hope to hear from you.<o:p></o:p> <o:p> </o:p> Kindly,<o:p></o:p> <o:p> </o:p> Vittorio<o:p></o:p> <o:p></o:p> <o:p></o:p> </div> <div> <o:p> </o:p> </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+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>. To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/e32370de-519b-4fd3-9176-438ddf027704n%40googlegroups.com?utm_medium=email&utm_source=footer"> https://groups.google.com/d/msgid/cp2k/e32370de-519b-4fd3-9176-438ddf027704n%40googlegroups.com</a>.<o:p></o:p> </div> </div> </div> </body> </html> -- You received this message because you are subscribed to the Google Groups "cp2k" group. 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