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

Last update: May 15, 2019

Mahfuzh Huda, Takuma Yagasaki, Masakazu Matsumoto, Hideki Tanaka

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

Crystals, 9(5), 248  (2019).

DOI:10.3390/cryst9050248

 

Ordinary substances shrink as the temperature decreases, but ice expands at very low temperatures. This phenomenon, called the negative thermal expansion of ice, is one of the abnormal properties of water. (Liquid water also exhibits a negative thermal expansion near the melting point.)


We calculate the thermal expansivity of ice I for the monatomic mW model using a 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.