On Tue, 2012-05-08 at 11:38 -0700, Milinda Samaraweera wrote: > Hi Guys > > > I was using the program http://q4md-forcefieldtools.org/RED/ to > derrive ESP based charges for some molecules that I study. Is this a > correct method to do so if not please let me know what are the other > methods that are available. >
Hi, this is really a hard questions to answer. Different methods to derive partial charges are present, which rely on various ideas. Actually, the partial charges of a force field should be consistent, because they are anyway just an approximation for the true charge density. Common force fields like AMBER or OPLS-AA were constructed with different consideration, giving rise to the differences, though they allow to desribe the same molecules. So I would study, how the remaining parameters of the applied force field were derived. Furthermore be aware that altering a single charge of force field might require readaption of dihedral and LJ parameters. Hence, always be careful and benchmark the force field against single as well collective static and dynamic properties, carefully. /Flo > > thanks alot > > Milinda Samaraweera > University of Connecticut > Department of Chemistry > 55 N Eagleville road > unit 3060 > Storrs CT > USA > -- > gmx-users mailing list [email protected] > http://lists.gromacs.org/mailman/listinfo/gmx-users > Please search the archive at > http://www.gromacs.org/Support/Mailing_Lists/Search before posting! > Please don't post (un)subscribe requests to the list. Use the > www interface or send it to [email protected]. > Can't post? Read http://www.gromacs.org/Support/Mailing_Lists -- Florian Dommert Dipl. - Phys. Institute for Computational Physics University Stuttgart Pfaffenwaldring 27 70569 Stuttgart EMail: [email protected] Homepage: http://www.icp.uni-stuttgart.de/~icp/Florian_Dommert Tel.: +49 - (0)711 - 68563613 Fax.: +49 - (0)711 - 68563658
signature.asc
Description: This is a digitally signed message part
-- gmx-users mailing list [email protected] http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to [email protected]. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
