A data structure, tangibly embodied in a computer-readable medium, representing a polymer of chemical units is disclosed. The data structure includes an identifier including a plurality of fields for storing values corresponding to properties of the polymer. The polymer may, for example, be a polysaccharide and the chemical units may be saccharides. Also disclosed is a computer-implemented method for determining whether properties of a query sequence of chemical units match properties of a polymer of chemical units. The query sequence is represented by a first data structure, and the polymer is represented by a second data structure, each are tangibly embodied in a computer-readable medium, including an identifier including a plurality of bit fields for storing values corresponding to properties of the query sequence and polymer, respectively. The invention also involves a notational system referred to as Property Encoded Nomenclature.