Iterative extended Hückel study of nucleic acid bases.
D000225:Adenine; D055598:Chemical Phenomena; D002621:Chemistry; D003596:Cytosine; D006147:Guanine; D008433:Mathematics; D013941:Thymine; D014498:Uracil
D014498:Uracil; D006147:Guanine; D003596:Cytosine; D000225:Adenine; D013941:Thymine