Density functional theory studies of methylated uracil: geometries and energies

Density functional theory studies on the geometries and energies of the met hylated derivatives of uracil yield two stable conformations, alpha and bet a, for each single-methylated uracil. They are different in the spatial ori entation of the substituting methyl group and the molecular total energy. A nalyzing the calculated structural parameters, we also found an elongation effect in the methylated uracil, which contributes to the increase of dipol e moment and molecular size of molecules such as the methylated derivatives of nucleic acid bases. (C) 2000 Elsevier Science B.V. All rights reserved.