Yong Zhang has published a paper ("A Simple AIMD Approach to Derive Atomic Charges for Condensed Phase Simulation of Ionic Liquids”, Journal of Physical Chemistry B, 2012, 116, 10036-10048) showing how partial charges can be obtained for ionic liquids using ab initio methods. More accurate results are obtained when the charges are derived from condensed phase simulations, but sampling liquid configurations is very time consuming. Yong shows in this work that accurate charges can be obtained from simulations of the crystalline phase, thereby saving a huge amount of time. Interestingly, properties such a diffusivity and melting point are more accurately modeled using the charges derived in this way than if other approaches are used.
Neeraj Rai and Surya Tiwari published a paper (Force Field Development for Actinyl Ions via Quantum Mechanical Calculations: An Approach to Account for Many Body Solvation Effects”, Journal of Physical Chemistry B, 2012, 116, 10885-10897) in which they showed how to develop a simple yet accurate pair potential for uranyl ions in water. Their approach uses explicitly solvated UO22+ ions along with MP2 energy scans to generate potential energy surfaces. These are then fit to a force field consisting of Lennard-Jones + partial charge terms. Condensed phase simulations show that the force field faithfully reproduces experimental liquid structure and solvation free energies.