Invariants and Molecular Characterization

In contrast to the representation of molecules by codes that are unique for each molecule, molecular characterization based on ordered sets of invariants need not be 

Figire 11. Graphs showing degeneracy with respect to a selected invariant. Z = Hosoya Z topological index, x = the connectivity index, ID = identification number, and prime ID is the identification number based on prime number weights. 

It may he of interest to mention here a historical note. Generalized matrices were considered before World War II in Russia by Balandin. He used different molecular properties that allowed bond partitioning and constructed the corresponding generalized matrices based on the entries of thus partitioned molecular properties.  

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