The water supercooled regime as described by four common water models

TL;DR

This study evaluates four common water models in the supercooled regime by introducing a temperature rescaling based on melting and heat capacity maxima, revealing TIP5P-Ew as the most accurate model.

Contribution

The paper proposes a novel temperature rescaling method for water models and compares their performance in the supercooled regime, highlighting TIP5P-Ew as the best representation.

Findings

TIP5P-Ew best matches supercooled water behavior after rescaling

All models show similar qualitative behavior in supercooled regime

Atomistic models rarely crystallize compared to coarse-grained models

Abstract

The temperature scale of simple water models in general does not coincide with the natural one. Therefore, in order to make a meaningful evaluation of different water models a temperature rescaling is necessary. In this paper we introduce a rescaling using the melting temperature and the temperature corresponding to the maximum of the heat capacity to evaluate four common water models (TIP4P-Ew, TIP4P-2005, TIP5P-Ew and Six-Sites) in the supercooled regime. Although all the models show the same general qualitative behavior, the TIP5P-Ew appears as the best representation of the supercooled regime when the rescaled temperature is used. We also analyze, using thermodynamic arguments, the critical nucleus size for ice growth. Finally, we speculate on the possible reasons why atomistic models do not usually crystalize while the coarse grained mW model do crystallize.