Molecular simulations of charged complex fluids: A review

Molecular simulation plays an increasingly important role in studying the properties of complex fluid systems containing charges, such as ions, piezoelectric materials, ionic liquids, ionic surfactants, polyelectrolytes, zwitterionic materials, nucleic acids, proteins, biomembranes and etc., where the electrostatic interactions are of special significance. Several methods have been available for treating the electrostatic interactions in explicit and implicit solvent models. Accurate and efficient treatment of such interactions has therefore always been one of the most challenging issues in classical molecular dynamics simulations due to their inhomogeneity and long-range characteristics. Currently, two major challenges remain in the application field of electrostatic interactions in molecular simulations; (i) improving the representation of electrostatic interactions while reducing the computational costs in molecular simulations; (ii) revealing the role of electrostatic interactions in regulating the specific properties of complex fluids. In this review, the calculation methods of electrostatic interactions, including basic principles, applicable conditions, advantages and disadvantages are summarized and compared. Subsequently, the specific role of electrostatic interactions in governing the properties and behaviors of different complex fluids is emphasized and explained. Finally, challenges and perspective on the computational study of charged systems are given.