Abstract:

The complexes stable structures were obtained, which were composed of calcium and magnesium bivalent cations and cytosine, by the optimization with density function theory at the B3LYP／6-311+G(2df,2p) level. The vibrational frequency was calculated, and the atoms vibration was analyzed. Some vibration modes belonging to the obvious frequencies of the complexes were discussed. According to the results, the frequencies obviously changed when the pyrimidine monomer acted with the cations. This mainly because the cations could take part in the molecule’s vibrations and change the force constants and effective mass.

Key words: density function; vibration; frequency; cytosine