XmlmmCIF equivalent: entity_poly_seq Data items in the ENTITY_POLY_SEQ category specify the sequence of monomers in a polymer. Allowance is made for the possibility of microheterogeneity in a sample by allowing a given sequence number to be correlated with more than one monomer id - the corresponding ATOM_SITE entries should reflect this heterogeneity. XmlmmCIF equivalent: entity_poly_seq/hetero A flag to indicate whether or not this monomer in the polymer is heterogeneous in sequence. This would be a rare phenomenon. XmlmmCIF equivalent: entity_poly_seq/entity_id This data item is a pointer to _entity.id in the ENTITY category. XmlmmCIF equivalent: entity_poly_seq/num The value of _entity_poly_seq.num must uniquely and sequentially identify a record in the ENTITY_POLY_SEQ list. Note that this item must be a number, and that the sequence numbers must progress in increasing numerical order. XmlmmCIF equivalent: entity_poly_seq/mon_id This data item is a pointer to _chem_comp.id in the CHEM_COMP category.