Energy transfer within the hydrogen bonding network of water following resonant terahertz excitation

Energy dissipation in water is very fast and more efficient than in many other liquids. This behavior is commonly attributed to the intermolecular interactions associated with hydrogen bonding. Here, we investigate the dynamic energy flow in the hydrogen bond network of liquid water by a pump-probe experiment. We resonantly excite intermolecular degrees of freedom with ultrashort single-cycle terahertz pulses and monitor its Raman response. By using ultrathin sample cell windows, a background-free bipolar signal whose tail relaxes monoexponentially is obtained. The relaxation is attributed to the molecular translational motions, using complementary experiments, force field, and ab initio molecular dynamics simulations. They reveal an initial coupling of the terahertz electric field to the molecular rotational degrees of freedom whose energy is rapidly transferred, within the excitation pulse duration, to the restricted translational motion of neighboring molecules. This rapid energy transfer may be rationalized by the strong anharmonicity of the intermolecular interactions.

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A Family of 3-DOF Translational Parallel Manipulators1

Journal of Mechanical Design ◽

10.1115/1.1563635 ◽

2003 ◽

Vol 125 (2) ◽

pp. 302-307 ◽

Cited By ~ 74

Author(s):

Marco Carricato ◽

Vincenzo Parenti-Castelli

Keyword(s):

Degrees Of Freedom ◽

Translational Motion ◽

Parallel Manipulators ◽

Geometric Interpretation ◽

The Other ◽

Six Degrees Of Freedom ◽

Revolute Joints ◽

Rotational Degrees Of Freedom

This article addresses parallel manipulators with fewer than six degrees of freedom, whose use may prove valuable in those applications in which a higher mobility is uncalled for. In particular, a family of 3-dof manipulators containing only revolute joints or at the most revolute and prismatic ones is studied. Design and assembly conditions sufficient to provide the travelling platform with a pure translational motion are determined and two sub-families that fulfill the imposed constraint are found: one is already known in the literature, while the other is original. The new architecture does not exhibit rotation singularities, i.e., configurations in which the platform gains rotational degrees of freedom. A geometric interpretation of the translation singularities is provided.

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Geometry of OH⋯O interactions in the liquid state of linear alcohols from ab initio molecular dynamics simulations

Physical Chemistry Chemical Physics ◽

10.1039/d0cp00435a ◽

2020 ◽

Vol 22 (12) ◽

pp. 6690-6697 ◽

Cited By ~ 3

Author(s):

Aman Jindal ◽

Sukumaran Vasudevan

Keyword(s):

Molecular Dynamics ◽

Hydrogen Bonding ◽

Ab Initio ◽

Molecular Dynamics Simulations ◽

Liquid State ◽

Crystalline State ◽

Md Simulations ◽

Ab Initio Molecular Dynamics ◽

Linear Alcohols ◽

Dynamics Simulations

Hydrogen bonding OH···O geometries in the liquid state of linear alcohols, derived from ab initio MD simulations, show no change from methanol to pentanol, in contrast to that observed in their crystalline state.

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Dissolution of cellulose in ionic liquids: an ab initio molecular dynamics simulation study

Physical Chemistry Chemical Physics ◽

10.1039/c4cp02219j ◽

2014 ◽

Vol 16 (33) ◽

pp. 17458-17465 ◽

Cited By ~ 39

Author(s):

Rajdeep Singh Payal ◽

Sundaram Balasubramanian

Keyword(s):

Molecular Dynamics ◽

Hydrogen Bonding ◽

Ionic Liquids ◽

Molecular Dynamics Simulation ◽

Ab Initio ◽

Simulation Study ◽

Molecular Hydrogen ◽

Dynamics Simulation ◽

Ab Initio Molecular Dynamics ◽

Dynamics Simulations

Dissolution of cellulose in ionic liquids involves breaking of its inter- and intra-molecular hydrogen bonding network, as seen through ab initio molecular dynamics simulations.

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Computational Design of High Energy RDX-Based Derivatives: Property Prediction, Intermolecular Interactions, and Decomposition Mechanisms

Molecules ◽

10.3390/molecules26237199 ◽

2021 ◽

Vol 26 (23) ◽

pp. 7199

Author(s):

Li Tang ◽

Weihua Zhu

Keyword(s):

Intermolecular Interactions ◽

Computational Design ◽

High Energy ◽

High Energy Density ◽

Ab Initio Molecular Dynamics ◽

Detonation Properties ◽

Cage Compounds ◽

High Energy Density Compounds ◽

Dynamics Simulations ◽

Low Sensitivity

A series of new high-energy insensitive compounds were designed based on 1,3,5-trinitro-1,3,5-triazinane (RDX) skeleton through incorporating -N(NO2)-CH2-N(NO2)-, -N(NH2)-, -N(NO2)-, and -O- linkages. Then, their electronic structures, heats of formation, detonation properties, and impact sensitivities were analyzed and predicted using DFT. The types of intermolecular interactions between their bimolecular assemble were analyzed. The thermal decomposition of one compound with excellent performance was studied through ab initio molecular dynamics simulations. All the designed compounds exhibit excellent detonation properties superior to 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), and lower impact sensitivity than CL-20. Thus, they may be viewed as promising candidates for high energy density compounds. Overall, our design strategy that the construction of bicyclic or cage compounds based on the RDX framework through incorporating the intermolecular linkages is very beneficial for developing novel energetic compounds with excellent detonation performance and low sensitivity.

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Vibrational couplings and energy transfer pathways of water’s bending mode

Nature Communications ◽

10.1038/s41467-020-19759-w ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Chun-Chieh Yu ◽

Kuo-Yang Chiang ◽

Masanari Okuno ◽

Takakazu Seki ◽

Tatsuhiko Ohto ◽

...

Keyword(s):

Energy Transfer ◽

Vibrational Energy ◽

Heat Bath ◽

Energy Relaxation ◽

Ab Initio Molecular Dynamics ◽

Vibrational Coupling ◽

Strongly Coupled ◽

Bending Mode ◽

Stretch Mode ◽

Dynamics Simulations

AbstractCoupling between vibrational modes is essential for energy transfer and dissipation in condensed matter. For water, different O-H stretch modes are known to be very strongly coupled both within and between water molecules, leading to ultrafast dissipation and delocalization of vibrational energy. In contrast, the information on the vibrational coupling of the H-O-H bending mode of water is lacking, even though the bending mode is an essential intermediate for the energy relaxation pathway from the stretch mode to the heat bath. By combining static and femtosecond infrared, Raman, and hyper-Raman spectroscopies for isotopically diluted water with ab initio molecular dynamics simulations, we find the vibrational coupling of the bending mode differs significantly from the stretch mode: the intramode intermolecular coupling of the bending mode is very weak, in stark contrast to the stretch mode. Our results elucidate the vibrational energy transfer pathways of water. Specifically, the librational motion is essential for the vibrational energy relaxation and orientational dynamics of H-O-H bending mode.

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Ab-Initio Molecular Dynamics Simulations and Calculations of Spectroscopic Parameters in Hydrogen-Bonding Liquids in Confinement (Project 8)

Zeitschrift für Physikalische Chemie ◽

10.1515/zpch-2017-1006 ◽

2018 ◽

Vol 232 (7-8) ◽

pp. 973-987 ◽

Cited By ~ 4

Author(s):

Daniel Sebastiani

Keyword(s):

Molecular Dynamics ◽

Hydrogen Bonding ◽

Molecular Dynamics Simulations ◽

Density Functional ◽

Ab Initio Molecular Dynamics ◽

Aqueous Mixtures ◽

Functional Theory ◽

Spatially Resolved ◽

Local Strength ◽

Dynamics Simulations

Abstract We investigate the effect of several nanoscale confinements on structural and dynamical properties of liquid water and binary aqueous mixtures. By means of molecular dynamics simulations based on density functional theory and atomistic force fields. Our main focus is on the dependence on the structure and the hydrogen-bonding-network of the liquids near the confinement interface at atomistic resolution. As a complementary aspect, spatially resolved profiles of the proton NMR chemical shift values are used to quantify the local strength of the hydrogen-bond-network.

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Selective filling of n-hexane in a tight nanopore

Nature Communications ◽

10.1038/s41467-020-20587-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Haoran Qu ◽

Archith Rayabharam ◽

Xiaojian Wu ◽

Peng Wang ◽

Yunfeng Li ◽

...

Keyword(s):

Molecular Dynamics ◽

Degrees Of Freedom ◽

Room Temperature ◽

Ab Initio Molecular Dynamics ◽

Bulk Solution ◽

Single Wall Carbon Nanotubes ◽

Unexpected Finding ◽

Low Probability ◽

Dynamics Simulations ◽

Molecular Sieving

AbstractMolecular sieving may occur when two molecules compete for a nanopore. In nearly all known examples, the nanopore is larger than the molecule that selectively enters the pore. Here, we experimentally demonstrate the ability of single-wall carbon nanotubes with a van der Waals pore size of 0.42 nm to separate n-hexane from cyclohexane—despite the fact that both molecules have kinetic diameters larger than the rigid nanopore. This unexpected finding challenges our current understanding of nanopore selectivity and how molecules may enter a tight channel. Ab initio molecular dynamics simulations reveal that n-hexane molecules stretch by nearly 11.2% inside the nanotube pore. Although at a relatively low probability (28.5% overall), the stretched state of n-hexane does exist in the bulk solution, allowing the molecule to enter the tight pore even at room temperature. These insights open up opportunities to engineer nanopore selectivity based on the molecular degrees of freedom.

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Observation of Field-Free Molecular Orientation by Terahertz Few-Cycle Pulses

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.554-556.1637 ◽

2012 ◽

Vol 554-556 ◽

pp. 1637-1642

Author(s):

Jie Yu ◽

Yong Liu ◽

Qian Zhen Su ◽

Shu Lin Cong

Keyword(s):

Schrödinger Equation ◽

Finite Temperature ◽

Molecular Orientation ◽

Schrodinger Equation ◽

Degrees Of Freedom ◽

Time Dependent ◽

Terahertz Pulses ◽

High Efficient ◽

Rotational Degrees Of Freedom

We demonstrate theoretically that the long-lived and efficient field-free molecular orientation can be realized by utilizing two few-cycle terahertz pulses (FCTPs) appropriately delayed in time at a finite temperature. The calculations are performed by solving the time-dependent Schrödinger equation including the vibrational and rotational degrees of freedom, with LiH as example. By adjusting these parameters of TFCP, a high efficient and long-lived molecular orientation can be obtained.

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A Family of 3-DOF Translational Parallel Manipulators

Volume 2A: 27th Design Automation Conference ◽

10.1115/detc2001/dac-21035 ◽

2001 ◽

Author(s):

Marco Carricato ◽

Vincenzo Parenti-Castelli

Keyword(s):

Degrees Of Freedom ◽

Translational Motion ◽

Parallel Manipulators ◽

Geometric Interpretation ◽

The Other ◽

Six Degrees Of Freedom ◽

Revolute Joints ◽

Rotational Degrees Of Freedom

Abstract This article addresses parallel manipulators with fewer than six degrees of freedom, whose employ may prove valuable in those applications in which a higher mobility is uncalled-for. In particular, a family of 3-dof manipulators containing only revolute joints or at the most revolute and prismatic ones is studied. Design and assembly conditions sufficient to provide the travelling platform with a pure translational motion are determined and two sub-families that fulfill the imposed constraint are found: one is already known in the literature, whilst the other is original. The new architecture does not exhibit rotation singularities, i.e. configurations in which the platform gains rotational degrees of freedom. A geometric interpretation of the translation singularities is provided.

Download Full-text