IMPROVED ABINITIO PAIR POTENTIALS FOR THE INTERACTION BETWEEN NUCLEIC-ACID BASES AND WATER

Intermolecular potentials to describe the interaction between nucleic acid bases and water are derived using ab initio calculations with a double-zeta plus one polarization function basis set. More than 2600 interaction energies are computed and fitted to a suitable analytical function. The quality of the fit is assessed by considering the iso-energy contour maps derived from the computed potentials. The potential energy functions are used to investigate the hydration patterns of the nucleic acid bases by means of Monte Carlo simulations. The preferential hydration sites are analyzed and discussed based on the pair correlation functions, running coordination numbers, and probability distribution maps.