A State-Specific PCM-DFT method to include dynamic solvent effects in the calculation of ionization energies: Application to DNA bases

A State-Specific PCM-DFT method taking into account dynamical solvent effects in the calculation of ionization energies (IEs) is reported. Mono-methylated nucleobases, representative of DNA blocks, are used as a test case. The accuracy of several functionals is tested, the M05-2X functional providing the most consistent performance. The inclusion of some molecules of the first hydration shell does not significantly affect the computed IE. The obtained vertical and adiabatic IEs are in good agreement with the available experimental and computational results, supporting the reliability of our method, enabling the calculation of first and upper ionization energies by using a single approach. (C) 2015 Published by Elsevier B.V.