Reference
Set the type of group to create,
container or
polytope.
A
container group is a recursive object that can contain
arbitrary sets of child objects such as groups, planes, directions,
atoms, bonds, texts.
A
polytope group builds a coordination polyhedron defined
by the smallest convex polygonal representation that surrounds
an arbitrary cloud of central and neighbour atoms.
Example: <group ... reference="container"/> (default)
Allowed values: container, polytope (optional)