Thermodynamic consistency in dissipative particle dynamics simulations of strongly nonideal liquids and liquid mixtures

Dissipative particle dynamics (DPD) is a mesoscopic simulation method for studying hydrodynamic behavior of complex fluids. Ideally, a mesoscopic model should correctly represent the thermo- and hydrodynamic properties of a real system beyond certain length and time scales. Traditionally defined DPD quite successfully mimics hydrodynamics, but is not flexible enough to accurately describe the thermodynamics of a real system. The so-called "multibody" DPD (MDPD) is a pragmatic extension of the classical DPD that allows one to prescribe the thermodynamic behavior of a system with only a small performance impact. Here we present a practical improvement to the "multibody" DPD model and test it on a number of single-component examples. We also generalize MDPD to multicomponent systems, which are an important target of DPD studies. The improved model provides a correction for particle correlations in strongly nonideal systems that were neglected in the original MDPD model. The implications of the coarse-graining procedure on the MDPD are discussed