Good question. Short answer, no -- LINCS doesn't play well with a velocity verlet based pressure control algorithm.
Long answer: MTTK has ended up not being robust because you need to solve a self consistent set of equations every timestep using the pressure estimator, which is extremely noisy, so it crashes randomly for no good reason. The good news is that I've done some fairly extensive testing, and leapfrog MD + Parrinello-Rahman + Nose-Hoover or vrescale is very close to the correct distribution -- there's really not that much difference for any practical purpose (I have a preprint with more details). The volume fluctuations are almost exactly right. So I think that for anything that doesn't require getting free energies to kJ/mol accuracy you are OK with that combination (just don't use Berendsen anything). Longer term (5.0), MTTK + shake will be removed -- its just too numerically unstable, and the self-consistent iteration part means it's very hard to parallelize. MTTK will be left in, but only without constraints. Hopefully, for 5.0 we will also have RESPA-like functionality, so that the bondeds can be performed at a higher frequency than the nonbondeds, which will be another useful way to get longer times steps. We also have planned to implement a Monte Carlo barostat, which will give exactly the correct NPT distribution for any integrator. Best, Michael On Fri, Jul 27, 2012 at 2:01 PM, Katie Maerzke <maerz...@gmail.com> wrote: > Hi all - > > Is there any plan to get LINCS working with the MTTK barostat in the near > future? > > Thanks > Katie > > -- > gmx-users mailing list gmx-users@gromacs.org > http://lists.gromacs.org/mailman/listinfo/gmx-users > * Only plain text messages are allowed! > * 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 gmx-users-requ...@gromacs.org. > * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users * Only plain text messages are allowed! * 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 gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
