Dimers and polymers

We have worked until now with a model of independent hard spheres. We can also form dimers where particles are paired with a thread which has a maximum length. Either:

Implement the simulation of a fluid of dimers.

Several hard spheres linked together by threads are a simple model used in polymer physics. Simulate a short polymer, with several spheres, in a bath of monomers.

Here, 6 monomers (red) are joined by a constraint such that their separation remains $|r|<3\sigma$. They are in a bath of blue monomers. $\sigma=0.4$.