Rethinking hydrogen-bond kinetics

TL;DR

This paper introduces a kinetic-based framework for analyzing water hydrogen bonds, avoiding arbitrary parameters, and reveals a consistent multi-exponential kinetic behavior.

Contribution

It presents a novel, parameter-free kinetic approach to studying hydrogen bonds, addressing inconsistencies in previous geometrical and energetic definitions.

Findings

Evidence for a self-consistent, multi-exponential kinetic behavior.

Framework based on commitment probabilities without arbitrary cutoffs.

Improved understanding of water hydrogen-bond dynamics.

Abstract

At the fundamental level, our understanding of water hydrogen-bond dynamics has been largely built on the detailed analysis of classical molecular simulations. The latter served to develop a plethora of hydrogen bond definitions based on different properties, including geometrical distances, topology and energetics. Notwithstanding, no real consensus emerged from these approaches, making the development of a consistent and reliable definition elusive. In this contribution, a framework to study hydrogen bonds in liquid water based purely on kinetics is presented. This approach makes use of the analysis of commitment probabilities without relying on arbitrarily chosen order parameters and cutoffs. Our results provide evidence for a self-consistent description, resulting in a clear multi-exponential behavior of the kinetics.