In GROMACS, I believe that whenever an external force is applied, the mean velocity of the group is subtracted before rescaling the velocities and then the mean velocity is added back in. So if you are expecting a plug like flow then there should not be any problem. In other cases also, it should not create a problem since your external electric field is not that large.
And yes you should not remove the center of mass motion of the molecules otherwise you will get zero velocity. Apoorv On Fri, Apr 22, 2011 at 2:09 AM, lammps lammps <lammp2fo...@gmail.com> wrote: > Hi, > > I want to use the option of E_x = 1 0.01 0 to add an electric field to > the simulated system in NVT ensemble. > > Because there should exist an no zero velocity of center-of-mass in the x > direction. It seems that it is wrong to directly use the nose-hoover to > control the temperature. > > it is also not reasonable to use nstcomm = 1, because the velocity of > center-of mass in the x-axis should be kept when runing. > > So, How to control the temperature? When calcating the temperature in the > process of simulations, how to exclude the velocity of center-of-mass of x > direction for controling the right T? > > Thanks in advance. > > -- > wade > > -- > gmx-users mailing list gmx-users@gromacs.org > 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 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 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
