[lammps-users] bead spring model

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1

I am simulating a simple melt of bead spring polymers and I was wondering if there is a built in function that will allow me to freeze some of the particles while allowing others to continue moving. Thanks

Ben Hanson

2

hi ben,

I am simulating a simple melt of bead spring polymers and I was wondering if there is a built in function that will allow me to freeze some of the particles while allowing others to continue moving. Thanks

there are a couple of ways to do that.

the simplest is probably, you define a group with the
particles that you want to keep moving and then use
this group only for time integration. all other particles
will still be included in the computation of forces but
their positions will not change.

similarly, you can use "fix setforce" to set forces for
a group of particles to 0.0. if the velocities of those
particles are also set to 0.0 before you start the run,
then they will not move.

cheers,
   axel.