Jmol/Cavities pockets and tunnels

From Proteopedia

Jmol can find and display cavities, pockets, and tunnels.

• Cavities are open spaces within a macromolecule, large enough to contain a water molecule, or much larger. The term "cavity" is sometimes used to include pockets and tunnels, but in a stricter usage, it means a space with no openings ("mouths") to the outside surface of the molecule.