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Melting points of water models: Current situation
S Blazquez1, C Vega1
1Dpto. Química Física I, Fac. Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
The Journal of Chemical Physics
|June 8, 2022
Summary
Researchers calculated melting points for several water models, finding none accurately predict both ice melting and maximum density temperatures. This highlights gaps in understanding water
Area of Science:
- Computational chemistry
- Materials science
- Physical chemistry
Background:
- Accurate water models are crucial for simulating various chemical and physical processes.
- Existing models often struggle to reproduce key properties of water, such as its melting point and density maximum.
Purpose of the Study:
- To calculate the melting points of ice Ih at normal pressure for recently proposed water models (TIP3P-FB, TIP4P-FB, TIP4P-D).
- To evaluate the performance of these and other models (TIP4P/2005, TIP5P) in reproducing critical water properties.
- To identify limitations in current water models and suggest future research directions.
Main Methods:
- Direct coexistence method for calculating melting points.
- Molecular dynamics simulations.
Main Results:
- Calculated melting points: TIP3P-FB (216 K), TIP4P-FB (242 K), TIP4P-D (247 K).
- Revisited melting points: TIP4P/2005 (250 K), TIP5P (274 K).
- No model simultaneously reproduced the melting temperature of ice Ih and the temperature of maximum density at room pressure.
Conclusions:
- Current water models are insufficient for simultaneously capturing the melting point and density anomaly.
- Further refinement of the potential energy surface of water is needed.
- Incorporating nuclear quantum effects may be necessary for accurate simulations.
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