MD simulations at atomistic and coarse grain level are rapidly converging towards multi-scale approaches. Hybrid models combine the best of two worlds, providing atomistic details in region of interest and coarser but much faster descriptions of less relevant parts of molecular systems. In 2010 we presented a CG model for water, which is based on the tetrahedral structure of water and was developed independently of atomistic models. Early in 2012 we showed that it is straightforwardly compatible with the popular SCP model for atomistic water.
We have just finished a complete set of simulations demonstrating that, despite differences in the relative free energy of mixing, also the TIP3P and SPC/E models are equally compatible with WT4. This extends the range of applicability of our hybrid solvation approach to most of the existing force fields for biomolecules.
In summary, WT4 can be used alone, as a CG model for solvation, or in combination with atomistic water models for dual resolution solvation approaches. These results will be sent for publication shortly
