scholarly journals Low-order many-body interactions determine the local structure of liquid water

2019 ◽  
Vol 10 (35) ◽  
pp. 8211-8218 ◽  
Author(s):  
Marc Riera ◽  
Eleftherios Lambros ◽  
Thuong T. Nguyen ◽  
Andreas W. Götz ◽  
Francesco Paesani
Keyword(s):  
Liquid Water ◽  
Local Structure ◽  
Quantum Effects ◽  
Many Body ◽  
Three Body ◽  
Many Body Interactions ◽  
Nuclear Quantum Effects ◽  
Structure Of Liquid ◽  
Low Order

Two-body and three-body energies, modulated by higher-body terms and nuclear quantum effects, determine the structure of liquid water and require sub-chemical accuracy that is achieved by the MB-pol model but not by existing DFT functionals.

Low-Order Many-Body Interactions Determine the Local Structure of Liquid Water

2019 ◽  
Author(s):  
Marc Riera ◽  
Eleftherios Lambros ◽  
Thuong T. Nguyen ◽  
Andreas W. Goetz ◽  
Francesco Paesani
Keyword(s):  
Total Energy ◽  
Liquid Water ◽  
Local Structure ◽  
Great Promise ◽  
Many Body ◽  
Hydrogen Bond Networks ◽  
The Many ◽  
Three Body ◽  
Many Body Interactions ◽  
Structure Of Liquid

<div> <div> <div> <p>Despite its apparent simplicity, water displays unique behavior across the phase diagram which is strictly related to the ability of the water molecules to form dense, yet dynamic, hydrogen- bond networks that continually fluctuate in time and space. The competition between different local hydrogen-bonding environments has been hypothesized as a possible origin of the anomalous properties of liquid water. Through a systematic application of the many-body expansion of the total energy, we demonstrate that the local structure of liquid water at room temperature is determined by a delicate balance between two-body and three-body energies, which is further modulated by higher-order many-body effects. Besides providing fundamental insights into the structure of liquid water, this analysis also emphasizes that a correct representation of two-body and three-body energies requires sub-chemical accuracy that is nowadays only achieved by many-body models rigorously derived from the many-body expansion of the total energy, which thus hold great promise for shedding light on the molecular origin of the anomalous behavior of liquid water. </p> </div> </div> </div>

Low-Order Many-Body Interactions Determine the Local Structure of Liquid Water

2019 ◽  
Author(s):  
Marc Riera ◽  
Eleftherios Lambros ◽  
Thuong T. Nguyen ◽  
Andreas W. Goetz ◽  
Francesco Paesani
Keyword(s):  
Total Energy ◽  
Liquid Water ◽  
Local Structure ◽  
Great Promise ◽  
Many Body ◽  
Hydrogen Bond Networks ◽  
The Many ◽  
Three Body ◽  
Many Body Interactions ◽  
Structure Of Liquid

<div> <div> <div> <p>Despite its apparent simplicity, water displays unique behavior across the phase diagram which is strictly related to the ability of the water molecules to form dense, yet dynamic, hydrogen- bond networks that continually fluctuate in time and space. The competition between different local hydrogen-bonding environments has been hypothesized as a possible origin of the anomalous properties of liquid water. Through a systematic application of the many-body expansion of the total energy, we demonstrate that the local structure of liquid water at room temperature is determined by a delicate balance between two-body and three-body energies, which is further modulated by higher-order many-body effects. Besides providing fundamental insights into the structure of liquid water, this analysis also emphasizes that a correct representation of two-body and three-body energies requires sub-chemical accuracy that is nowadays only achieved by many-body models rigorously derived from the many-body expansion of the total energy, which thus hold great promise for shedding light on the molecular origin of the anomalous behavior of liquid water. </p> </div> </div> </div>

scholarly journals The Anomalies and Local Structure of Liquid Water from Many-Body Molecular Dynamics Simulations

2021 ◽  
Author(s):  
Thomas E. Gartner III ◽  
Kelly M. Hunter ◽  
Eleftherios Lambros ◽  
Alessandro Caruso ◽  
Marc Riera ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Liquid Water ◽  
Local Structure ◽  
Ambient Pressure ◽  
Liquid Density ◽  
Many Body ◽  
The Many ◽  
Dynamics Simulations ◽  
Structure Of Liquid

For the last 50 years, researchers have sought molecular models that can accurately reproduce water’s microscopic structure and thermophysical properties across broad ranges of its complex phase diagram. Herein, molecular dynamics simulations with the many-body MB-pol model are performed to monitor the thermodynamic response functions and local structure of liquid water from the boiling point down to deeply supercooled temperatures at ambient pressure. The isothermal compressibility and isobaric heat capacity show maxima at ~223 K, in excellent agreement with recent experiments, and the liquid density exhibits a minimum at ~208 K. Furthermore, a local tetrahedral arrangement, where each water molecule accepts and donates two hydrogen bonds, is the most probable hydrogen-bonding topology at all temperatures. This work suggests that MB-pol may provide predictive capability for studies of liquid water’s physical properties across broad ranges of thermodynamic states.

scholarly journals Atomic-state-dependent screening model for hot and warm dense plasmas

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Fuyang Zhou ◽  
Yizhi Qu ◽  
Junwen Gao ◽  
Yulong Ma ◽  
Yong Wu ◽  
...  
Keyword(s):  
Radiation Transport ◽  
Atomic State ◽  
Many Body ◽  
Dense Plasmas ◽  
Screening Model ◽  
State Dependent ◽  
Recombination Processes ◽  
Three Body ◽  
Many Body Interactions ◽  
Body Recombination

AbstractAn ion embedded in warm/hot dense plasmas will greatly alter its microscopic structure and dynamics, as well as the macroscopic radiation transport properties of the plasmas, due to complicated many-body interactions with surrounding particles. Accurate theoretically modeling of such kind of quantum many-body interactions is essential but very challenging. In this work, we propose an atomic-state-dependent screening model for treating the plasmas with a wide range of temperatures and densities, in which the contributions of three-body recombination processes are included. We show that the electron distributions around an ion are strongly correlated with the ionic state studied due to the contributions of three-body recombination processes. The feasibility and validation of the proposed model are demonstrated by reproducing the experimental result of the line-shift of hot-dense plasmas as well as the classical molecular dynamic simulations of moderately coupled ultra-cold neutral plasmas. Our work opens a promising way to treat the screening effect of hot and warm dense plasma, which is a bottleneck of those extensive studies in high-energy-density physics, such as atomic processes in plasma, plasma spectra and radiation transport properties, among others.

scholarly journals Nuclear quantum effects on the vibrational dynamics of liquid water

2018 ◽  
Vol 148 (10) ◽  
pp. 102328 ◽  
Author(s):  
Deepak Ojha ◽  
Andrés Henao ◽  
Thomas D. Kühne
Keyword(s):  
Liquid Water ◽  
Quantum Effects ◽  
Vibrational Dynamics ◽  
Nuclear Quantum Effects

scholarly journals Disentangling Coupling Effects in the Infrared Spectra of Liquid Water

2018 ◽  
Author(s):  
Kelly M. Hunter ◽  
Farnaz A. Shakib ◽  
Francesco Paesani
Keyword(s):  
Liquid Water ◽  
Electrostatic Interactions ◽  
Synergistic Effects ◽  
Potential Energy Function ◽  
Many Body ◽  
Nuclear Quantum Effects ◽  
Different Levels ◽  
Isotopic Water ◽  
Mechanical Nature

<div> <div> <div> <p>A quantitative characterization of intermolecular and intramolecular couplings that modulate the OH-stretch vibrational band in liquid water has so far remained elusive. Here, we take up this challenge by combining the centroid molecular dynamics (CMD) formalism, which accounts for nuclear quantum effects, with the MB-pol potential energy function, which accurately reproduces the properties of water across all phases, to model the infrared (IR) spectra of various isotopic water solutions with different levels of vibrational couplings, including those that cannot be probed experimentally. Analysis of the different IR OH-stretch lineshapes provides direct evidence for the partially quantum-mechanical nature of hydrogen bonds in liquid water, which is emphasized by synergistic effects associated with intermolecular coupling and many-body electrostatic interactions. Furthermore, we quantitatively demonstrate that intramolecular coupling, which results in Fermi resonances due to the mixing between HOH-bend overtones and OH-stretch fundamentals, are responsible for the shoulder located at ∼3250 cm<sup>-1</sup> of the IR OH-stretch band of liquid water. </p> </div> </div> </div>

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