Dear LAMMPS users,
I intend to completely cover a large sphere with lots of middle size spheres - name it as cluster. And the small spheres fill in the other space of the simulation box. On one hand, these middle size spheres cannot leave the large sphere, so the “body particle” might be applicable. But on the other hand, I also need to measure and tune the Young’s module of the cluster by compress the simulation box. In this sense, I hope that I can tune the interaction between the middle size spheres and the large sphere, and this is not applicable if I set the cluster as a body particle. So is it possible that I can set the cluster as a kind of body particle but I can tune the interaction between the middle size spheres and the large sphere? Thank you very much.
Best regards,
zjgbz
Dear LAMMPS users,
I intend to completely cover a large sphere with lots of middle size
spheres - name it as cluster. And the small spheres fill in the other space
of the simulation box. On one hand, these middle size spheres cannot leave
the large sphere, so the “body particle” might be applicable.
at the moment, there is no significant benefit for the setup you describe
in using a body particle over using fix rigid (or any of its variants).
the only integrator that exists is equivalent to fix rigid. for more
complex operations, e.g. bodies that can be deformed, you will need to
write a custom integrator (and come up with a suitable model/theory for the
equations of motion of that).
But on the other hand, I also need to measure and tune the Young’s module
of the cluster by compress the simulation box. In this sense, I hope that I
can tune the interaction between the middle size spheres and the large
sphere, and this is not applicable if I set the cluster as a body particle.
So is it possible that I can set the cluster as a kind of body particle but
I can tune the interaction between the middle size spheres and the large
sphere? Thank you very much.
if you have a rigid object, there is nothing to tune but the non-bonded
interactions of the constituent particles.
on the other hand, you could also model the kind of system you describe, by
having all your "outer" particles connected with the central particle
through an explicit bond. then the force constant of that bond would
determine how easily your particle can be deformed. depending on how
"fluid" you want the particles on the surface to be, you could have them
only interact via non-bonded interactions, or use a "mesh" of bonds, there
as well.
axel.
Hi Axel,
Connecting the “outer” particles with the large central particle by bonds sounds reasonable and easier. Thank you very much!
Best regards,
zjgbz