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Published on: January 26, 2016
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Structural entropy of glassy systems from graph isomorphism
1Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802, USA. stm9@psu.edu.
Soft Matter
|August 12, 2016
Summary
We developed a graph-theory method to calculate structural entropy in glass-forming liquids. This method quantifies local structure, revealing insights into the glass transition dynamics.
Area of Science:
- Physics
- Materials Science
- Computational Chemistry
Background:
- Configurational entropy is crucial for understanding the glass transition.
- It quantifies the number of potential energy landscape basins.
- Evaluating configurational entropy involves counting distinct inherent structures.
Purpose of the Study:
- To propose a novel graph-theory based method for calculating structural entropy.
- To examine local structure and entropy in hard-particle systems.
- To determine if structural entropy is non-zero at the dynamic glass transition.
Main Methods:
- Utilizing graph theory to analyze local structures in hard-particle systems.
- Classifying Voronoi diagrams of clusters using graph isomorphism algorithms.
- Calculating structural entropy (SG) from cluster statistics.
Main Results:
- Identified structural motifs like icosahedron-like order.
- Found that structural entropy (SG) of an n-particle subsystem grows linearly with n.
- Determined structural entropy per particle (dSG/dn) for hard-disk and hard-sphere systems.
Conclusions:
- The proposed graph-theory method provides a reliable way to calculate structural entropy.
- Structural entropy per particle is non-zero at the dynamic glass transition for hard-particle systems.
- Results align with previous configurational entropy calculations using thermodynamic integration.
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