# Weak links between fast mobility and local structure in molecular and atomic liquids.

@article{Bernini2015WeakLB, title={Weak links between fast mobility and local structure in molecular and atomic liquids.}, author={Sebastiano Bernini and Francesco Puosi and Dino Leporini}, journal={The Journal of chemical physics}, year={2015}, volume={142 12}, pages={ 124504 } }

We investigate by molecular-dynamics simulations, the fast mobility-the rattling amplitude of the particles temporarily trapped by the cage of the neighbors-in mildly supercooled states of dense molecular (linear trimers) and atomic (binary mixtures) liquids. The mixture particles interact by the Lennard-Jones potential. The non-bonded particles of the molecular system are coupled by the more general Mie potential with variable repulsive and attractive exponents in a range which is a…

## Figures from this paper

## 10 Citations

Cage effect in supercooled molecular liquids: Local anisotropies and collective solid-like response.

- PhysicsThe Journal of chemical physics
- 2016

It is concluded that the cage rattling is largely affected by solid-like extended modes, in close resemblance with experimental findings on colloids.

Thermodynamic scaling of vibrational dynamics and relaxation.

- PhysicsThe Journal of chemical physics
- 2016

An expression of the TS master curve of the structural relaxation with one adjustable parameter less than the available three-parameter alternatives is derived and fits well with the experimental TS master curves of thirty-four glassformers and, in particular, their slope at the glass transition, i.e., the isochoric fragility.

Anisotropy of the monomer random walk in a polymer melt: local-order and connectivity effects

- PhysicsJournal of physics. Condensed matter : an Institute of Physics journal
- 2016

The results strongly suggest that the sole consideration of the local order is not enough to understand the microscopic origin of the rattling amplitude of the trapped monomer in the cage of the neighbours.

Dynamical, structural and chemical heterogeneities in a binary metallic glass-forming liquid

- Materials ScienceJournal of physics. Condensed matter : an Institute of Physics journal
- 2018

A structural analysis of slow clusters based on Voronoi tessellation evidences an increase with respect of the bulk system of the fraction of Cu atoms having a local icosahedral order in the dynamic slowing-down in supercooled metal alloys.

Dynamics of glass-forming liquids: Will theory and experiment ever meet?

- Physics
- 2018

The overall theme of this work has been to experimentally test the shoving model and isomorph theory related to the dynamics of glass-forming liquids, both of which, rather than being universal…

Short-Time Elasticity of Polymer Melts: Tobolsky Conjecture and Heterogeneous Local Stiffness

- Materials Science
- 2015

An extended Molecular-Dynamics study of the short-time "glassy" elasticity exhibited by a polymer melt of linear fully-flexible chains above the glass transition is presented. The focus is on the…

Thermodynamic scaling of relaxation: insights from anharmonic elasticity

- ChemistryJournal of physics. Condensed matter : an Institute of Physics journal
- 2017

This work proposes a method for evaluating both the characteristic exponent and the TS master curve that uses experimentally accessible quantities that characterise the anharmonic elasticity and does not use details about the microscopic interactions.

Elucidation of the Nature of Structural Relaxation in Glassy D-Sorbitol.

- Materials ScienceThe journal of physical chemistry. B
- 2020

A novel approach is applied for exploring nontrivial interactions between structural units in d-sorbitol, a canonical example of a hydrogen-bonded organic glass, by introducing a dihedral-rearrangement indicator analysis to shed light on relaxation processes and dynamical heterogeneity.

The kinetic fragility of liquids as manifestation of the elastic softening

- Materials ScienceThe European physical journal. E, Soft matter
- 2015

We show that the fragility m , the steepness of the viscosity and relaxation time close to the vitrification, increases with the degree of elastic softening, i.e. the decrease of the elastic modulus…

Universal nature of dynamic heterogeneity in glass-forming liquids: A comparative study of metallic and polymeric glass-forming liquids.

- Materials ScienceThe Journal of chemical physics
- 2019

An examination of particles having a locally preferred atomic packing, and clusters of such particles, suggests that there is no one-to-one relation between these populations of particles so that an understanding of the origin of DH in terms of static fluid structure remains elusive.

## References

SHOWING 1-10 OF 289 REFERENCES

Scaling between structural relaxation and particle caging in a model colloidal gel

- Physics
- 2010

In glassy dynamics, the rattling of particles in a cage formed by their neighbors is typically limited to a length scale of the order of the particle diameter but is nevertheless strongly coupled to…

Locally preferred structures and many-body static correlations in viscous liquids.

- PhysicsPhysical review. E, Statistical, nonlinear, and soft matter physics
- 2011

It is found that the growth of domains formed by interconnected locally preferred structures signals the onset of the slow-dynamics regime and allows the rationalization of the different dynamic behaviors of the models.

Spatial displacement correlations in polymeric systems.

- PhysicsThe Journal of chemical physics
- 2012

It is shown that states with identical average vibrational monomer displacement exhibit identical spatial correlations of the monomer displacements pertaining to the subsets of the fast and the slow monomers characterizing both the short-time and the long-time dynamical heterogeneities.

Non-Gaussian effects in the cage dynamics of polymers

- Physics
- 2008

The correlation between the fast cage dynamics and structural relaxation is investigated in a model polymer system. It is shown that the cage vibration amplitude, as expressed by the Debye–Waller…

Scaling between relaxation, transport, and caged dynamics in polymers: from cage restructuring to diffusion.

- PhysicsThe journal of physical chemistry. B
- 2011

The analysis carried out in terms of the van Hove function shows that the scaling does not depend on the specific quantity used to quantify both the relaxation times and the amplitude of the rattling motion, thus extending analogous results already known for atomic liquids.

Static and dynamic density effects due to the finite length of polymer chains: a molecular-dynamics investigation

- Materials Science
- 2004

The finite length of polymer chains affects both the static and the relaxation properties of the density of the melt state. These have been investigated by molecular-dynamics simulations of a…

Scaling between relaxation, transport and caged dynamics in a binary mixture on a per-component basis.

- PhysicsThe Journal of chemical physics
- 2013

The present study shows that the scaling does not need information concerning the arbitrarily-defined glass transition region and relies on a single characteristic length scale a(2)(1/2) which is determined even far from that region and provides a link between the fast dynamics and the thermodynamic scaling of the slow dynamics.

Competition of the connectivity with the local and the global order in polymer melts and crystals.

- Materials ScienceThe Journal of chemical physics
- 2013

The competition between the connectivity and the local or global order in model fully flexible chain molecules is investigated by molecular-dynamics simulations and reveals that increasing the number of shell bonds decreases the FCS order in both melt and crystal.

Dynamics of entangled linear polymer melts: A molecular‐dynamics simulation

- Physics
- 1990

We present an extensive molecular‐dynamics simulation for a bead spring model of a melt of linear polymers. The number of monomers N covers the range from N=5 to N=400. Since the entanglement length…

Free volume properties of a linear soft polymer: a computer simulation study.

- PhysicsThe Journal of chemical physics
- 2004

Molecular dynamics simulation of a linear soft polymer has been performed and the free volume properties of the system have been analyzed in detail in terms of the Voronoi polyhedra of the monomers.…