<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=iso-8859-1"> <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 Léon<o:p></o:p> <o:p> </o:p> Note that LAMMPS uses a d<a href="https://docs.lammps.org/angle_harmonic.html">ifferent potential definition</a>. By contrast to CP2K, LAMMPS includes the prefactor ½ into the constant K.<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: cp2k@googlegroups.com <cp2k@googlegroups.com> on behalf of Léon Luntadila Lufungula <Leon.luntadilalufungula@uantwerpen.be> Date: Friday, 12 January 2024 at 09:53 To: cp2k <cp2k@googlegroups.com> Subject: [CP2K:19726] Correct TIP3P parameters<o:p></o:p> </div> Dear all,<o:p></o:p> <div> <o:p> </o:p> </div> <div> Just a quick question about the parameters for the TIP3P forcefield. In the example files (see attached water.inp) of the <a href="https://www.cp2k.org/exercises:2019_uzh_acpc2:ex02">exercise</a> on molecular simulation of water the TIP3P model is used to simulate water. In the input file, I noticed that the force constant of the H-O-H bend and the H-O bond are 110 rad^-2kcalmol and 900 angstrom^-2kcalmol, respectively. However, when looking online for the parameters like on the <a href="https://docs.lammps.org/Howto_tip3p.html">lammps documentation</a>, I find that these values are actually half of what is defined in the input, i.e., 55 rad^-2kcalmol and 450 angstrom^-2kcalmol, respectively... Is this indeed an error in the input file or am I missing something here? Most water input files I see in the tests/Fist folder also contain the smaller values for the force constants.<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> Kind regards,<o:p></o:p> </div> <div> Léon<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/2bed3d68-2c9d-4ceb-8672-208cfe7d0fd8n%40googlegroups.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/2bed3d68-2c9d-4ceb-8672-208cfe7d0fd8n%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. 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/ZRAP278MB082790AB0CCB5530397DF493F46F2%40ZRAP278MB0827.CHEP278.PROD.OUTLOOK.COM?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/ZRAP278MB082790AB0CCB5530397DF493F46F2%40ZRAP278MB0827.CHEP278.PROD.OUTLOOK.COM</a>.