Negative Thermal Expansivity of Ice: Comparison of the Monatomic mW Model with the All-Atom TIP4P/2005 Water Model

Muhammad Mahfuzh Huda,Takuma Yagasaki,Hideki Tanaka,Masakazu Matsumoto

doi:10.3390/cryst9050248

Muhammad Mahfuzh Huda, Takuma Yagasaki + Show 2 more

Open Access

https://doi.org/10.3390/cryst9050248

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Journal: Crystals	Publication Date: May 14, 2019
Citations: 1	License type: CC BY 4.0

Affiliation: Okayama University

Abstract

We calculate the thermal expansivity of ice I for the monatomic mW model using the quasi-harmonic approximation. It is found that the original mW model is unable to reproduce the negative thermal expansivity experimentally observed at low temperatures. A simple prescription is proposed to recover the negative thermal expansion by re-adjusting the so-called tetrahedrality parameter, λ. We investigate the relation between the λ value and the Grüneisen parameter to explain the origin of negative thermal expansion in the mW model and compare it with an all-atom water model that allows the examination of the effect of the rotational motions on the volume of ice.

Highlights

Liquid water freezes into ice I under ambient pressure
We demonstrate that the coupling between the two types of modes plays a vital role for the negative thermal expansivity of ice
It is of interest to examine if the monatomic water (mW) model can reproduce the negative thermal expansivity and how to revise it to lead to its better reproducibility

Summary

Introduction

Liquid water freezes into ice I under ambient pressure. One of interesting characteristics of ice I is its negative thermal expansivity at low temperatures [1,2,3,4,5]. The computational cost of the mW model is quite low because the number of interaction sites is reduced and because the long-range interactions are omitted This model reproduces various properties of ice I well, such as the melting point. We demonstrate that the coupling between the two types of modes plays a vital role for the negative thermal expansivity of ice. Our aim in this work is to explore how the mW model works in low temperatures by examining the thermal expansivity of ice. The original potential for the Si atom has been made, and the negative thermal expansion is recovered for amorphous Si only [28]. It is of interest to examine if the mW model can reproduce the negative thermal expansivity and how to revise it to lead to its better reproducibility

Force Field Models and Structure of Ice

Quasi-Harmonic Approximation

Results

Thermodynamics

Discussion

Frequency

Conclusions