David, that's exactly right. For every timestep value, one can derive the appropriate upper limit for the restraint constant in a somewhat physically sound manner.
I am just not entirely sure what was the purpose of the initial question, because for "infinite" restraint constant, I'd just freeze the particle. Actually, come to think of it, my Planck time estimate for Mother Nature's timestep in vibrating bonds is probably incorrect. Effective bond length over the speed of light is more like it. :) Alex DvdS> But it boils down to that if you make the force constant very large you DvdS> need to make the time step short too which may not be what you want. >> -- 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.
