EPR-refined atomistic molecular dynamics delivers predictive spectroscopy in self-organized soft matter systems
Mark R. Wilson, Vasily S. Oganesyan
Cell Reports Physical Science, Vol. 7, Issue 6, pp. 103332–103332 (2026)
10.1016/j.xcrp.2026.103332
Abstract
Electron paramagnetic resonance (EPR) spectroscopy with nitroxide spin probes is a sensitive probe of structural dynamics in soft matter. Here, we report the use of EPR to test and refine atomistic molecular dynamics (MD) force fields for the discotic liquid crystal 2,3,6,7,10,11 hexa(hexyloxy)triphenylene (HAT6). We show that subtle variations in partial charge schemes, aromatic core Lennard-Jones interactions, and alkoxy torsional potentials cause pronounced changes in predicted EPR line shapes. By comparing experimental and MD-predicted spectra at a reference temperature, we identify refined parameters that reproduce both the measured spectra and the isotropic-columnar phase transition temperature. The predictions reveal pretransitional growth of short molecular stacks in the isotropic phase and the emergence of columnar order on cooling. This work establishes EPR spectroscopy as a powerful benchmark for testing and improving molecular force fields to deliver fully atomistic predictions of variable temperature EPR spectra of a discotic liquid crystal.
Topics
Field: Physics and Astronomy · Subfield: Atomic and Molecular Physics, and Optics
Keywords
Molecular dynamics,Soft matter,Spectroscopy,Dynamics (music),Work (physics)
UN Sustainable Development Goals
- Climate action (0.45)
All Available Versions
- Landing page — Cell Reports Physical Science publishedVersion cc-by
- Landing page — Durham Research Online (Durham University) submittedVersion cc-by
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