Figure 3. Molecular graph for the aldo-pentose sugars. L-lyxose deprotonated at C2-HO2 (h), D-ribose deprotonated at C3-HO3 and C4-HO4 (m,n), and L-arabinose deprotonated at C3-HO3 site (e) exhibit bifurcated intramolecular H-bonds. While other conjugate bases of aldo-pentose show conventional intramolecular H-bonds. Small red spheres and lines correspond to the BCPs and bond paths.