Structural analysis of water networks

TL;DR

This paper explores the structural properties of water networks using graph theory, providing a detailed topological and geometrical analysis to understand water's anomalies and phase behaviors.

Contribution

It advances previous work by applying diverse connectivity, centrality, and global metrics to deepen the understanding of water network structures through graph-theoretic methods.

Findings

Identification of water phases via graph metrics

Enhanced topological characterization of water networks

Application of multiple graph measures for structural analysis

Abstract

Liquid water, besides being fundamental for life on Earth, has long fascinated scientists due to several anomalies. Different hypotheses have been put forward to explain these peculiarities. The most accredited one foresees the presence in the supercooled region of two phases at different densities: the low-density liquid phase and the high-density liquid phase. In our previous work [Faccio et al., J. Mol. Liq. 355 (2022): 118922], we showed that it is possible to identify these two forms in water networks through a computational approach based on molecular dynamics simulation and on the calculation of the total communicability of the associated graph, in which the nodes correspond to water molecules and the edges represent the connections (interactions) between molecules. In this paper, we present a more in-depth investigation of the application of graph-theory based approaches to the analysis of the structure of water networks. In particular, we investigate different connectivity and centrality measures and we report on the use of a variety of global metrics aimed at giving a topological and geometrical characterization of liquid water.