Lammps users:
I have a simulation where I have 2 separate groups. One group is pretty much the bulk medium. The second group is a single molecule with a set linear AND angular momentum. How do I set (and maintain) the initial linear velocity and angular velocity of all of the atoms within the molecule of interest, while thermostatting the rest of the system as normal?
I know with the velocity command you can give the molecule a linear velocity, but I can’t find a way to give the molecule a rotational velocity and keep that velocity constant throughout the simulation.
I know with fix_momentum I can make the momentum zero, but I need to the velocity then keep that momentum.
Any help would be great, and if you need more details, I’ll accommodate as best I can.
Kevin
Lammps users:
I have a simulation where I have 2 separate groups. One group is pretty
much the bulk medium. The second group is a single molecule with a set
linear AND angular momentum. How do I set (and maintain) the initial linear
velocity and angular velocity of all of the atoms within the molecule of
interest, while thermostatting the rest of the system as normal?
kevin,
what you describe is a molecule that doesn't interact with anything.
why do a simulation like that in the first place?
in general, it is almost always better to describe and ask about what
you want to model instead of asking about how to do something specific.
cheers,
axel.
If you can treat the molecule as rigid, then fix rigid gives you the option
to not change the linear and angular momentum of a rigid body.
So if it starts out spinning, it will continue to spin.
Steve