Packing structures and transitions in liquids and solids.

Area of Science:

• Condensed matter physics
• Materials science
• Physical chemistry

Background:

• Condensed phase properties are typically understood through macroscopic measurements.
• The inherent structure of liquids is often obscured by thermal motion.
• Understanding molecular arrangements is key to explaining material behavior.

Purpose of the Study:

• To establish a unifying principle for condensed phase properties based on molecular packing.
• To identify the inherent structure within liquids.
• To explain the thermodynamic nature of melting/freezing and glass transitions.

Main Methods:

• Classification of potential energy minima.
• Analysis of mechanically stable molecular packings.
• Mapping topological distributions of transitions between potential minima.

Main Results:

• Identified an inherent structure in liquids by analyzing molecular packings.
• Demonstrated that melting and freezing involve characteristic packing sequences.
• Linked defect-softening phenomena to the first-order nature of phase transitions.
• Explained glass transitions and relaxation via the distribution of transitions between minima.

Conclusions:

• Molecular packing classification provides a fundamental framework for condensed matter.
• This approach elucidates the microscopic origins of macroscopic phenomena like phase transitions and glass behavior.
• The study offers a new perspective on the relationship between structure and dynamics in condensed phases.