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Updated: Mar 3, 2026
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A Microfluidic Approach for the Study of Ice and Clathrate Hydrate Crystallization
Published on: August 18, 2022
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Non-Markovian dynamics in ice nucleation
Pablo Montero de Hijes1, Sebastian Falkner2, Christoph Dellago3
1Faculty of Physics, University of Vienna, A-1090 Vienna, Austria.
The Journal of Chemical Physics
|March 2, 2026
Summary
Classical nucleation theory assumes nucleus size dynamics are Markovian. This study reveals non-Markovian dynamics in homogeneous ice nucleation, suggesting nucleus size is not a sufficient reaction coordinate.
Area of Science:
- Physical Chemistry
- Computational Physics
- Materials Science
Background:
- The size of the largest crystalline nucleus is a common reaction coordinate in crystallization simulations.
- Classical nucleation theory often assumes Markovian dynamics for this coordinate.
Purpose of the Study:
- To investigate if nucleus size dynamics in homogeneous ice nucleation are Markovian.
- To identify slow modes and develop improved reaction coordinates.
Main Methods:
- Molecular dynamics simulations of 300 independent ice nucleation trajectories.
- Analysis of mean recurrence times and structural descriptors.
- Neural network training to learn the committor function.
- Symbolic regression for developing an approximate committor.
Main Results:
- Nucleus size dynamics exhibit history dependence, indicating non-Markovian behavior.
- Systematic differences observed in nucleus structures between early and late recurrences.
- Identification of collective variables and a compact approximation of the committor.
Conclusions:
- Nucleus size alone is insufficient as a reaction coordinate for homogeneous ice nucleation.
- The identified collective variables and approximate committor offer improved descriptors for nucleation dynamics.
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