[lammps-users] Regarding periodic box

Dear all,

I am simulating a system that contains polymers and beads with two atom types. Polymer is made up of one atom-type, and the beads are of another atom type. All the atom types have interaction modeled by pair style LJ; the polymer has only repulsive LJ. The system has a concentration of phi=0.2, and it is a periodic simulation. The polymer behaves like SAW (self-avoiding walk) polymer and expands and interacts with the polymer in the periodic image.

Is this simulation wrong? If I had to calculate the number of beads bound on the polymer over time, would it give inaccurate results?

Rakesh K.

Nothing about your description seems wrong. The number of beads in the polymer will not change due to the fact that it is interacting with itself across a periodic boundary. An interesting variation on this is if the polymer backbone is connected to itself across a periodic boundary. This might seem like a cyclic polymer, but it is actually a polymer of infinite length with somewhat unphysical long-range translational order. This might be an acceptable condition for certain purposes.