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My P-Lincs paper http://dx.doi.org/10.1021/ct700200b shows that<br>with order 6 and a time step of 4 fs you get roughly the same constraint accuracy<br>and energy conservation as without v-sites and a 2 fs time step.<br>With order 4 and a 4 fs time step the energy drift is 2.2 times higher than with order 6<br>(not mentioned in the paper). This is not a very large difference.<br><br>I recall that some time ago I decided to change the default lincs order to 6<br>(I have not done this yet), but unfortunately now I don't recall what issue<br>made me decide that the current default accuracy is not high enough.<br><br>Berk<br><br>> Date: Wed, 7 Oct 2009 13:16:52 +0200<br>> From: jochen@xray.bmc.uu.se<br>> To: gmx-users@gromacs.org<br>> Subject: [gmx-users] vsites and lincs-order<br>> <br>> Hi,<br>> <br>> the manual suggests lincs-order = 6 when using large time steps (4-5 fs, <br>> with vsites). Has anyone experience how severe that issue is. Has anyone <br>> observed artefacts with lincs-order=4 and large time steps?<br>> <br>> Thanks a lot,<br>> <br>> Jochen<br>> <br>> -- <br>> ---------------------------------------------------<br>> Dr. Jochen Hub<br>> Molecular Biophysics group<br>> Dept. of Cell & Molecular Biology<br>> Uppsala University. Box 596, 75124 Uppsala, Sweden.<br>> Phone: +46-18-4714451 Fax: +46-18-511755<br>> ---------------------------------------------------<br>> <br>> _______________________________________________<br>> gmx-users mailing list gmx-users@gromacs.org<br>> http://lists.gromacs.org/mailman/listinfo/gmx-users<br>> Please search the archive at http://www.gromacs.org/search before posting!<br>> Please don't post (un)subscribe requests to the list. Use the <br>> www interface or send it to gmx-users-request@gromacs.org.<br>> Can't post? Read http://www.gromacs.org/mailing_lists/users.php<br> <br /><hr />What can you do with the new Windows Live? <a href='http://www.microsoft.com/windows/windowslive/default.aspx' target='_new'>Find out</a></body>
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