Introducing a force-matched united atom force field to explore larger spatiotemporal domains in molecular dynamics simulations of bitumen

Assaf Martinez-Streignard, E.I.; Liu, X.; Lin, P.; Erkens, S.

doi:10.1016/j.matdes.2024.112831

Introducing a force-matched united atom force field to explore larger spatiotemporal domains in molecular dynamics simulations of bitumen

Title

Introducing a force-matched united atom force field to explore larger spatiotemporal domains in molecular dynamics simulations of bitumen

Author

Assaf Martinez-Streignard, E.I. (TU Delft Pavement Engineering)
Liu, X. (TU Delft Pavement Engineering)
Lin, P. (TU Delft Pavement Engineering; Rijkswaterstaat)
Erkens, S. (TU Delft Pavement Engineering; Rijkswaterstaat)

Date

2024

Abstract

This paper presents a United Atom (UA) force field for simulating hydrocarbon molecules in bituminous materials, integrating explicit hydrogens into beads with their parent atom. This method simplifies all-atom molecular models, significantly accelerating Molecular Dynamics (MD) simulations of bitumen by 10 to 100 times. Key advantages include halving the particle count, eliminating complex hydrogen interactions, and decreasing the degrees of freedom of the molecules. Developed by mapping forces from an all-atom model to the centers of mass of UA model beads, the force field ensures accurate replication of energies, forces, and molecular conformations, mirroring properties like pressure and density. It features 17 bead types and 287 interaction types, encompassing various hydrocarbon molecules. The UA force field's stability, surpassing all-atom models, is a notable achievement. This stability, stemming from smoother potential energy surfaces, leads to consistent property measurements and improved stress tensor accuracy. It enables the extension of MD simulations to larger spatiotemporal scales, crucial for understanding complex phenomena such as phase separation in bituminous materials. This foundational work sets the stage for future developments, including refining parameters and introducing new bead types, to enhance the modeling capabilities of the force field, thereby advancing the application and understanding of bituminous materials.

Subject

Bitumen
Coarse-graining
Force field
Force-matching
Molecular dynamics
Morphology
Phase separation
Segregation

To reference this document use:

http://resolver.tudelft.nl/uuid:c8ee6c57-73b0-4ae3-9030-595a4b2a696a

DOI

https://doi.org/10.1016/j.matdes.2024.112831

ISSN

0264-1275

Source

Materials & Design, 240

Part of collection

Institutional Repository