XmlmmCIF equivalent: pdbx_entity_assembly The PDBX_ENTITY_ASSEMBLY category provides a chemical description of the biological assembly studied in terms of its constituent entities. XmlmmCIF equivalent: pdbx_entity_assembly/biol_id An identifier for the assembly. XmlmmCIF equivalent: pdbx_entity_assembly/num_copies The number of copies of this entity in the assembly. XmlmmCIF equivalent: pdbx_entity_assembly/id An identifier for the assembly. XmlmmCIF equivalent: pdbx_entity_assembly/entity_id An enity identifier. A reference to _entity.id.