On the development of polarizable and Lennard-Jones force fields to study hydration structure and dynamics of actinide(III) ions based on effective ionic radii.

In this contribution, we show how it is possible to develop polarizable and non-polarizable force fields to study hydration properties of a whole chemical series based on atomic properties such as ionic radii. In particular, we have addressed the actinide(III) ion series, from U3+ to Cf3+, for which X-ray absorption data and effective ionic radii are available. A polarizable force field has been re-parameterized improving the original one [M. Duvail et al., J. Chem. Phys. 135, 044503 (2011)] which was based on solid state ionic radii. The new force field does not depend on solid state properties but directly on the liquid phase ones, and it can be used to study these ions in liquid water without any ambiguity. Furthermore, we have shown that it is possible to parameterize also a non-polarizable potential using standard Lennard-Jones and Coulombic forces, which can be transferred to other systems in condensed phase. The structural and dynamical properties of these two force fields are compared to each other and with data available in the literature, providing a good agreement. Moreover, we show the comparison with experimental X-ray absorption data that are very well reproduced by both force fields.