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An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Characterizing molecular motion in H2O and H3O+ with dynamical instability statistics
Jason R Green1, Thomas S Hofer, R Stephen Berry
1Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3100, USA.
The Journal of Chemical Physics
|November 18, 2011
Summary
Finite-time Lyapunov exponents reveal distinct molecular dynamics. Chaos is higher near isomerization saddles and lower near potential energy minima in H2O and H3O+ systems.
Area of Science:
- Chemical Physics
- Molecular Dynamics
- Chaos Theory
Background:
- Finite-time Lyapunov exponents (FTLEs) are crucial for analyzing the stability and instability of chaotic dynamical systems.
- Understanding molecular dynamics is essential for predicting chemical reactions and properties.
Purpose of the Study:
- To investigate the subpopulations within FTLE distributions for small isolated molecules.
- To correlate these subpopulations with distinct elementary molecular motions, such as isomerizations.
- To explore the relationship between potential energy landscapes and chaotic dynamics.
Main Methods:
- Calculated FTLEs from constant total energy molecular dynamics simulations.
- Utilized classical, reactive, all-atom potentials for H2O and H3O+.
- Analyzed exponent distributions across a range of total energies.
Main Results:
- Identified subpopulations in FTLE sample distributions corresponding to different molecular dynamics.
- Observed more chaotic phase space exploration near isomerization saddles.
- Found less chaotic dynamics near potential energy minima for H2O and H3O+.
Conclusions:
- FTLE subpopulations can identify distinct elementary motions in small molecules.
- The potential energy landscape significantly influences the chaotic nature of molecular dynamics.
- Findings contrast with previous studies on Lennard-Jones clusters, highlighting system-specific behaviors.
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