The Importance of Tetrahedrally Coordinated Molecules for the Explanation of Liquid Water Properties

Abstract

Ab initio calculations on molecular clusters and a quantum statistical model are used to probe the structure of liquid water and its anomalies. Characteristic temperature dependent mixtures of ring and three-dimensional, voluminous water clusters provide the famous density maximum. The mixture model also reproduces the shift of the density maximum as a function of pressure and isotopic substitution. This finding is consistent with femtosecond spectroscopy data suggesting that two distinct molecular species exist in liquid water. The given structures also reproduce the oxygen-oxygen pair correlation function and the vibrational IR spectrum of liquid water. The results underline the importance of three-dimensional, tetrahedrally coordinated structures for the understanding of water anomalies and the existence of two liquid phases in the supercooled region.

Influence of Gas Supply Changes on the Formation Process of Complex Mixed Gas Hydrates

“…These labile clusters agglomerate by sharing faces until they reach a critical size for hydrate growth. The assumption is also supported by other studies where the existence of water cavities arranged in a pentagonal dodecahedron [36] and ring structures [37] were postulated.…”

Hydrogen-bond relaxation dynamics: Resolving mysteries of water ice

“…Authoritative reviews on the advancement in this field have focused on the following issues from various perspectives: from water structures [51][52][53], molecular clusters [54][55][56][57], ice nucleation and growth [22,58], ice melting [59], slipperiness and friction of ice [60], to the behavior of water ice subjected to positive [61,62] and negative pressure [54,63]. Reviews have also covered topics on water surface charge and polarization 8 [64,65], surface photoelectron emission [66,67], phonon relaxation [24,68], water adsorption onto inorganic surfaces [69][70][71][72][73], and ion effects on water properties and structures [74], among other topics.…”

Quantum cluster equilibrium model of N-methylformamide–water binary mixtures

“…at least once in order to capture the fundamental physics of the system. Since pure water has already been extensively studied using the QCE method, [56][57][58][59][60][61][62][63][64][65][66][67][68] we chose a set of clusters that was found to be important in those earlier studies. It consists of the monomer (w1), the dimer (w2), two ring structures (w5, w6), a cube (w8) and a bicyclic cluster (w9), which we call spiro cluster because of its similarity to organic spiro compounds.…”