An indicator to whether the whole assembly that is modeled is fit into the 3DEM map
or if only a subset of the structural assembly is fit into the map.
This data item is a pointer to _ihm_struct_assembly.assembly_id in the
IHM_STRUCT_ASSEMBLY category. The IHM_STRUCT_ASSEMBLY category provides the
details regarding the different structural assemblies used in the modeling.
The default value for this data item is "1" indicating that the entire assembly
being modeled is fit into the EM map.