Quantum model helps solve mysteries of water

water
Credit: George Hodan/public domain

Water is one of the most common and extensively studied substances on earth. It is vital for all known forms of life but its unique behaviour has yet to be explained in terms of the properties of individual molecules.

Water derives many of its signature features from a combination of properties at the molecular level such as high polarizability, directional hydrogen bonding sites and van der Waals forces, the attractive or between molecules not related to covalent or .

Many models exist that can reproduce certain aspects of these properties but there is no 'ultimate model' that can reproduce them all. NPL scientists have collaborated on a radical new 'bottom up' approach that could help form a more complete model.

The research, published in Physical Review Letters, explains how a single charged particle, known as a 'quantum Drude oscillator' (QDO), can mimic the way that the electrons of a real water molecule fluctuate and respond to their environment.

This apparently extreme simplification retains interactions, not normally accessible in classical descriptions, and appears sufficiently powerful for the properties of liquid water to emerge naturally under ambient conditions. A realistic liquid is produced with a well-developed network of hydrogen bonds and other properties in close agreement to those of water such as the surface tension and the heat at which water evaporates into steam.

Quantum model reveals surface structure of water
Heterogeneous electronic density created by the diverse molecular orientations at the liquid-vapor interface of water. Credit: NPL/University of Edinburgh

This approach could potentially be used for other substances and offers a new framework for simulation of materials at the atomic and molecular scale.

The computations for this research were performed as part of an early access grant on Blue Joule, the fastest computer in the UK, which is in the Science & Technology Facilities Council's Hartree Centre.


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Quantum model helps solve mysteries of water

Journal information: Physical Review Letters

Citation: Quantum model helps solve mysteries of water (2015, April 20) retrieved 25 May 2019 from https://phys.org/news/2015-04-quantum-mysteries.html
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Apr 20, 2015
A single charged particle equates to M Mathis' photon being charged. http://milesmathi...ired.pdf
"...., since I have shown that the 19 to 1 ratio applies not to some form of
exotic new matter, it applies to the photon/matter ratio. "
Hmmmm, a reprint of this article from 2 year ago? http://phys.org/n...ies.html
I do like the idea of charge bonding replacing covalent bonding,

Apr 21, 2015
I have many prior Physorg posts concerning Art Winfree's law of coupled periodic oscillators, in which I apply his law to physics. The "quantum Drude oscillator" model deployed in the above article is consistent with my idea.

Winfree's law is a simplified mathematical approach describing the coherent behavior of all systems of periodic oscillators, developed circa 1967. Winfree and others (e.g. Bard Ermentrout) applied the law to biology. Steve Strogatz (Cornell, applied math) has confirmed and extended Winfree's math.

Years ago, I proposed that Winfree's law applies broadly to physics, including particularly quantum physics, on the ground that Planck's quantum of energy is itself a "periodic oscillation."

Thus the success of the quantum (Drude) oscillation model indirectly supports my idea. I have many Physorg posts, dating back to 2010, in which I show how Winfree's law may explain "surprising" results in recent physics investigations.

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