The multiple local structures in liquid water

Abstract

The debate over whether the structure of liquid water is homogeneous or mixed with a variety of structures has been going on for more than one century. With the discovery of different amorphous ices and advances in computer technology, mixture model is gaining more and more attention. In this paper, the latest progress in the experiment and simulation of the local structure of liquid water is introduced firstly. Secondly, the principal component analysis is used to study the water’s Raman spectra and tetrahedral-order distributions. We find that both the spectra and distributions can be obtained by linear superposition of two basic functions, which correspond to the existence of two local structures in liquid water. Finally, we introduce the development of using the binary regular solution theory to explain some thermodynamic properties of liquid water.