Low, high and very-high density forms of liquid water revealed by a medium-range order descriptor

We present in this paper a computational approach based on molecular dynamics simulations and graph theory to characterize the structure of liquid water considering not only the local structural arrangement within the first (or second) hydration shell, but also the medium- to long-range order. In pa...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2021-10
Main Authors: Faccio, Chiara, Benzi, Michele, Zanetti-Polzi, Laura, Daidone, Isabella
Format: Article
Language:English
Subjects:
Density
Graph theory
Liquid phases
Long range order
Molecular dynamics
Order parameters
Phase transitions
Water
Water chemistry
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We present in this paper a computational approach based on molecular dynamics simulations and graph theory to characterize the structure of liquid water considering not only the local structural arrangement within the first (or second) hydration shell, but also the medium- to long-range order. In particular, a new order parameter borrowed from the graph-theory framework, i.e. the node total communicability (NTC ), is introduced to analyze the dynamic network of water molecules in the liquid phase. This order parameter is able not only to accurately report on the different high-density-liquid (HDL) and low-density-liquid (LDL) water phases postulated in the liquid-liquid phase transition hypothesis, but also to unveil the presence of very high density liquid (VHDL) clusters, both under pressure and at ambient conditions. To the best of our knowledge, VHDL water patches under moderate pressures were not observed before.
ISSN:2331-8422