Microscopic structure and dynamics of high and low density trans-1,2-dichloroethylene liquids

TL;DR

This study investigates how the microscopic structure and molecular dynamics of trans-1,2-dichloroethylene liquids vary between high and low densities using neutron scattering and simulations, revealing more cooperative behavior in high density conditions.

Contribution

It combines neutron scattering experiments with molecular dynamics simulations to elucidate the relationship between density, structure, and dynamics in trans-1,2-dichloroethylene liquids.

Findings

High density liquids exhibit more cooperative molecular motions.

Structural changes correlate with dynamic behavior shifts.

Backscattering due to molecular correlations underpins cooperative motions.

Abstract

We present a study of the dynamics and structural changes for trans-1,2-dichloroethylene between high and low density liquids using neutron scattering techniques (diffraction, small angle neutron scattering and time of flight spectroscopy) and molecular dynamics simulations. We show that changes in the short range ordering of molecules goes along with a change of the molecular dynamics: both structure and dynamics of the high density liquid are more cooperative than those of the low density liquid. The microscopic mechanism underlying the cooperative motions in the high density liquid has been found to be related to the backscattering of molecules due to a strong correlation of molecular ordering.