Calculation of pressure exerted on a flexible polymer network

Dear all,

I am trying to calculate the stress on a polymer network that is being used to filter colloidal particles with different velocities. To do this, I am using the stress/atom command, which calculates the stress*volume quantity. For the volume, can I simply sum the volumes of all the colloidal particles that are used to form the network?

That is certainly an option that you can do, but this is a question for MD in general and not LAMMPS. The best answer will be to refer to the literature, an advisor, and/or a textbook and consider what metric is most physically relevant to your specific system then document your decision.

I think you can use the compute voronoi/atom command in lammps to make a voronoi decomposition of your system. Then you can dump the per atom stresses and the coresponding voronoi cell volume multiply them and compute the local stress per atom using a post prosess tool. But this is for the calculation of the local stress if this is what you need.