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Published on: January 15, 2014
Topological defects and bulk melting of hexagonal ice
Davide Donadio1, Paolo Raiteri, Michele Parrinello
1Computational Science, Department of Chemistry and Applied Biosciences, ETH Zürich, USI Campus, Via Buffi 13, CH-6900 Lugano, Switzerland. ddonadio@phys.chem.ethz.ch
The Journal of Physical Chemistry. B
|July 21, 2006
Summary
Bulk melting in hexagonal ice involves topological defects that maintain the tetrahedral network. These defects cluster, forming a stable region that eventually triggers the transition to a liquid state.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Computational Chemistry
Background:
- Understanding the phase transitions of water ice is crucial for various scientific disciplines.
- Hexagonal ice (Ice Ih) is the most common form of ice under ambient conditions.
- The precise mechanism of ice melting at the molecular level remains an active area of research.
Purpose of the Study:
- To investigate the molecular mechanisms underlying the bulk melting of hexagonal ice.
- To elucidate the role of topological and coordination defects in the melting process.
- To utilize advanced computational methods for simulating ice phase transitions.
Main Methods:
- Classical molecular dynamics simulations.
- Application of the metadynamics method for enhanced sampling.
- Analysis of defect formation and evolution during melting.
Main Results:
- Bulk melting of hexagonal ice is mediated by the formation of topological defects.
- These defects preserve the tetrahedral coordination of the ice network.
- Defects cluster into stable regions of approximately 50 molecules, exhibiting long lifetimes.
- The subsequent emergence of coordination defects initiates the transition to the liquid state.
Conclusions:
- Topological defects play a critical role in initiating the melting of hexagonal ice.
- The metadynamics method provides valuable insights into the complex dynamics of phase transitions.
- The findings offer a detailed molecular-level understanding of ice melting, contributing to the broader field of condensed matter physics.
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