Ultra-Coarse-Grained Liquid State Models with Implicit Hydrogen Bonding.

Area of Science:

• Computational Chemistry
• Materials Science
• Statistical Mechanics

Background:

• Coarse-graining (CG) methods accelerate molecular simulations by reducing atomistic detail.
• However, CG models can lose crucial configurational information, such as hydrogen bond network topology.
• This loss hinders accurate representation of liquid properties dependent on specific interactions.

Purpose of the Study:

• To develop novel ultra-coarse-grained (UCG) models that retain hydrogen bonding information.
• To enable CG simulations to capture structural properties arising from sub-resolution configurations.
• To address limitations of standard CG approaches in modeling directional interactions.

Main Methods:

• Introduction of internal states within UCG sites to represent hydrogen bond donor/acceptor configurations.
• Modeling internal states in quasi-equilibrium, controlled by local UCG site density.
• Development of UCG models for chain-like and ring-like hydrogen bonding motifs.

Main Results:

• UCG models successfully reproduced structural properties of five liquid systems.
• The models captured properties originating from all-atom resolution configurations.
• Demonstrated ability to represent hydrogen bonding motifs beyond averaged interactions.

Conclusions:

• UCG models with internal states offer a powerful approach to preserve hydrogen bonding details in simulations.
• This methodology enhances the accuracy of CG simulations for liquids with specific interactions.
• The UCG framework is applicable to complex systems like biomolecules where hydrogen bonding is critical.