CAD based initialization of molecular zones

I would like to share a CAD based method developed by us for initialization of molecular dynamics simulation. In this method CAD or 3D object is placed in the molecular zone leading to creation of
positive and negative CAD zones. The positive CAD zone is the molecular zone occupied by the
CAD / 3D object while the negative CAD zone is represented by the rest or unoccupied molecular zone.

For example, consider a sphere object in the molecular zone as shown in the figure. The negative CAD
zone is filled by the water molecules while the positive CAD zone is filled by the C540 Fullerene molecule.
The negative CAD filling can start from a pre-determined position from the wall based on fluid-wall interaction

In a second example, consider a CAD object representing a nano-nozzle as shown in the figure. Here the positive CAD zone is filled with simple lattice of solid Argon while the negative CAD zone is occupied by the Argon gas.

The CAD based initialization once incorporated in mdFOAM code can be of good help
to our group in carrying out molecular dynamics simulation for complicated geometries.