Back-mapping augmented adaptive resolution simulation

Area of Science:

• Computational Chemistry
• Molecular Dynamics
• Multiscale Modeling

Background:

• Concurrent multiscale techniques like Adaptive Resolution Scheme (AdResS) offer computational advantages over atomistic (AT) simulations.
• AdResS methods often require hybrid regions for numerical stability during atomistic degrees of freedom (DOFs) re-insertion.
• Random DOF insertion can lead to overlapping AT potentials, posing challenges for simulation accuracy.

Purpose of the Study:

• To develop a novel method for direct coupling of atomistic and coarse-grained resolutions in multiscale simulations.
• To address the numerical instability issues arising from random DOF insertion at the resolution interface.
• To enhance the accuracy and applicability of AdResS simulations.

Main Methods:

• Proposed the Energy Minimized AT (DOF) Insertion (EMATI) method.
• EMATI utilizes informed insertion of AT DOFs to resolve overlapping potential issues.
• Implemented and tested AdResS-EMATI in a liquid butane system.

Main Results:

• AdResS-EMATI demonstrated improved structural and thermodynamic properties at the interface compared to existing AdResS approaches.
• The method enables direct coupling of AT and coarse-grained resolutions without modifying interaction potentials.
• Successfully extended AdResS applicability to systems where force capping is insufficient.

Conclusions:

• EMATI provides a robust solution for direct multiscale coupling, eliminating the need for hybrid regions.
• This advancement enhances the reliability and scope of AdResS simulations.
• The informed DOF insertion strategy significantly improves interface properties in multiscale modeling.