Solvation of cytosine and thymine using a combined Discrete/SCRF model

The solvation of cytosine and thymine has been investigated using a combined Discrete/SCRF model. Four cytosine–H2O complexes, one cytosine–5H2O complex and two thymine–H2O complexes were obtained from geometry optimizations at the HF/6-31G(d) level. The PCM self-consistent reaction-field were applied to such complexes in order to investigate the effects of the explicit water on the free energy of solvation and on the electronic structure of the solute.