CUR - The Council on Undergraduate Research

Development of Coarse-Grained Bulk Water Model Using New Hybrid Coarse-Graining Approach

Austin Haley, Sergiy Markutsya, College of Engineering, University of Kentucky, 4810 Alben Barkley Drive P.O. Box 7380 Paducah, KY 42002

Water is one of the most common solvent used for industrial purposes. Development of an accurate and efficient water molecule force field for use in the molecular dynamics (MD) simulations is a challenging task. There is a number of different models for bulk water that are available for use in MD simulations. However, none of the available models are capable of satisfying the following three requirements at once: accuracy, efficiency, and simplicity. The objective of this research is to develop a computationally efficient force field for a water model from ab initio quantum chemistry data. This new model would accurately predict structure, dynamic, thermodynamic, and transport properties. To perform this task, multi-scale coarse-graining approach (MSCG) has been applied to ab initio quantum chemistry data. In MSCG atoms are grouped into beads, thus, reducing the number of degrees of freedom. For an accurate structure prediction, a new hybrid scheme has been applied combining MSCG method with an iterative Boltzmann inversion (IBI) coarse-graining method. Bulk water model developed by the new hybrid coarse-graining approach (MSCG+IBI) accurately predicts structure properties. New hybrid method is capable to recover spatial distribution of different molecules (non-bonded interactions) as well as bonds distributions within the same molecule (bonded interactions). Moreover, a proposed hybrid approach may be applied to variety of coarse-graining methods and to systems with different temperatures. With such flexibility, a hybrid method may be used for various systems of interest where accurate prediction of structure properties is essential.

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