Hi, That's always your call. You perform equilibration to swap between MM (energy minimization) and MD (kinetic energy). In the other word you slowly start MD and prevent unwanted and unrealistic rearrangement in your system. If initial positions are important - you restrain the interesting molecules. If you equilibrate for example lipid bilayer - there is no reason to do that. Often you can also totally skip equilibration and just cut off a few initial ns. Sometimes you make nvt, npt and still cut off beginning and sometimes you perform MD to find optimal system, in which case the whole simulation is in fact equilibration. You know your system, you have to consider if restraining movement is what you need. Best, KM
2018-02-09 13:28 GMT+01:00 sanjeet kumar singh ch16d012 < ch16d...@smail.iitm.ac.in>: > Hi list, > > I am preparing an amorphous sample using GROMACS but i am in doubt that > during the equilibration stage ( NVT & NPT ) do i need to put position > restraint on my polymer as there are no solvent in my system and if i have > to use position restraint then why i should do that? > > THANKS, > SK > -- > Gromacs Users mailing list > > * Please search the archive at http://www.gromacs.org/ > Support/Mailing_Lists/GMX-Users_List before posting! > > * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists > > * For (un)subscribe requests visit > https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or > send a mail to gmx-users-requ...@gromacs.org. > -- Jagiellonian University Department of Computational Biophysics and Bioinformatics tel.1: (12) 664 61 49 tel.2: (48) 664 086 049 -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.