Relation between the High Density Phase and the Very-High Density Phase of Amorphous Solid Water

TL;DR

This study uses computer simulations to investigate the structural relationships among different amorphous ice phases, supporting the view that VHDA is a more stable form of HDA and related to HDL water.

Contribution

The paper provides computational evidence that VHDA is a stable form of HDA, clarifying its relation to HDL water and challenging the idea of a distinct high-density amorphous phase.

Findings

VHDA is a more stable form of HDA

VHDA should be considered as amorphous HDL

Supports the HDL-LDA hypothesis over the existence of a separate VHDA phase

Abstract

It has been suggested that high-density amorphous (HDA) ice is a structurally arrested form of high-density liquid (HDL) water, while low-density amorphous (LDA) ice is a structurally arrested form of low-density liquid (LDL) water. Recent experiments and simulations have been interpreted to support the possibility of a second "distinct" high-density structural state, named very high-density amorphous (VHDA) ice, questioning the LDL-HDL hypothesis. We test this interpretation using extensive computer simulations, and find that VHDA is a more stable form of HDA and that in fact VHDA should be considered as the amorphous ice of the quenched HDL.