Collineations of particles in the Kob-Andersen system

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Subtle structural changes in supercooled liquids are linked to the glass transition.
• Understanding these changes is key for developing new glass materials.
• Previous work focused on short particle chains (collineations), but longer chains remain understudied.

Purpose of the Study:

• To systematically investigate long collineations in supercooled liquids.
• To compare collineations in parent and inherent structures.
• To model the relationship between collineations and density distribution functions.

Main Methods:

• Simulation of the Kob-Andersen system.
• Analysis of parent and inherent structures during cooling.
• Development and application of a model connecting collineations to pair and angular density distributions.
• Study of particle diffusion and collineation lifetimes.

Main Results:

• Below the potential energy landscape crossover temperature, parent structures exhibit more collineations than inherent structures.
• A developed model accurately describes long collineations using density distribution functions.
• Particles in collineations diffuse slightly slower than average particles.
• Collineation lifetimes show vibrational and structural relaxation regimes.
• No clear connection was found between collineations and disclination lines, low-energy clusters, or cooperative motion.

Conclusions:

• Long collineations play a significant role in the structure of supercooled liquids.
• The findings challenge intuitive expectations regarding collineations in different structural descriptions.
• The developed model provides a useful tool for analyzing collineations.