Energy Renormalization for Coarse-Graining the Dynamics of a Model Glass-Forming Liquid.

ABSTRACT: Coarse-grained modeling achieves the enhanced computational efficiency required to model glass-forming materials by integrating out "unessential" molecular degrees of freedom, but no effective temperature transferable coarse-graining method currently exists to capture dynamics. We address this fundamental problem through an energy-renormalization scheme, in conjunction with the localization model of relaxation relating the Debye-Waller factor ?u2? to the structural relaxation time ?. Taking ortho-terphenyl as a model small-molecule glass-forming liquid, we show that preserving ?u2? (at picosecond time scale) under coarse-graining by renormalizing the cohesive interaction strength allows for quantitative prediction of both short- and long-time dynamics covering the entire temperature range of glass formation. Our findings provide physical insights into the dynamics of cooled liquids and make progress for building temperature-transferable coarse-grained models that predict key properties of glass-forming materials.

SUBMITTER: Xia W 

PROVIDER: S-EPMC6217959 | biostudies-other | 2018 Feb

REPOSITORIES: biostudies-other