title: The crystal structures of purines, pyrimidines and their intermolecular complexes.
mesh_terms: D001463:Barbiturates; D055598:Chemical Phenomena; D002621:Chemistry; D008433:Mathematics; D008961:Models, Structural; D009696:Nucleic Acids; D011687:Purines; D011743:Pyrimidines; D014961:X-Ray Diffraction
chemical_list: D001463:Barbiturates; D009696:Nucleic Acids; D011687:Purines; D011743:Pyrimidines