The simulation consists of carbon atoms, initially in the liquid state (high temperature). The temperature of the system is decreased progressively until hexagonal rings form. It results in an amorphous nanoporous structure of carbon.
Run the input.lammps file using LAMMPS, and visualise the 'dump' output using VMD. If you are new to LAMMPS and VMD, you can find tutorials and instructions here.
This video has been made with this script.
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