Energy dissipation in water is very fast and more efficient than many other liquids. This behavior commonly attributed to the intermolecular interactions associated with hydrogen bonding. Here, we investigate dynamic energy flow bond network of liquid by a pump-probe experiment. We resonantly excite degrees freedom ultrashort single-cycle terahertz pulses monitor its Raman response. By using ultrathin sample cell windows, background-free bipolar signal whose tail relaxes monoexponentially...

Water at negative pressures can remain in a metastable state for surprisingly long time before it reaches equilibrium by cavitation, i.e., the formation of vapor bubbles. The wide spread experimentally measured cavitation depending on water purity, surface contact angle, and quality implicates relevance bulk, surfaces, defects different systems. We formulate kinetic model that includes all three pathways determine nucleation attempt frequencies from atomistic molecular dynamics simulations....

Dielectric water properties, which significantly change in confinement, determine electrostatic interactions and thereby influence all molecular forces chemical reactions. We present comparative simulations of between graphene sheets, decanol monolayers, phospholipid glycolipid bilayers. Generally, dielectric profiles strongly differ perpendicular parallel surface directions for large separation decay to the bulk value 1–2 nm away from surface. Polar groups enhance local interfacial response...

The poor performance of many existing nonpolarizable ion force fields is typically blamed on either the lack explicit polarizability, absence charge transfer, or use unreduced Coulomb interactions. However, this analysis disregards large and mostly unexplored parameter range offered by Lennard-Jones potential. We a global optimization procedure to develop water-model-transferable for ions K+, Na+, Cl–, Br– in complete space all interactions using standard mixing rules. No extra-thermodynamic...

One essential ingredient in many machine learning (ML) based methods for atomistic modeling of materials and molecules is the use locality. While allowing better system-size scaling, this systematically neglects long-range (LR) effects such as electrostatic or dispersion interactions. We present an extension long distance equivariant (LODE) framework that can handle diverse LR interactions a consistent way seamlessly integrates with preexisting by building new sets atom centered features....

Absorption spectra of liquid water at 300 K are calculated from both classical and density functional theory molecular dynamics simulation data, which together span 1 MHz to hundreds THz, agreeing well with experimental data qualitativley quantitavely over the entire range, including IR modes, microwave peak, intermediate THz bands. The decomposed into single-molecular collective components as due reorientations changes in induced intramolecular dipole moments. These decompositions shed new...

Many vital processes taking place in electrolytes, such as nanoparticle self-assembly, water purification, and the operation of aqueous supercapacitors, rely on precise many-body interactions between surfaces ions water. Here we study interaction a hydrated ion charge-neutral graphene layer using atomistic molecular dynamics simulations. For small separations, ion–graphene repulsion is nonelectrostatic nature, for intermediate van der Waals attraction becomes important. Contrary to...

Molecular dynamics simulations in conjunction with effective medium theory are used to investigate dielectric effects water-filled nanotubes. The resulting axial constant shows a divergent increase for small nanotube radii that depends on the length, while radial decreases significantly thin By solving Poisson's equation an anisotropic cylindrical geometry, we show ion-ion interaction separations primarily constant, not one. This means electrostatic interactions nanotubes linear level...

Although important for atmospheric processes and gas-phase catalysis, very little is known about the hydration state of ions in vapor phase. Here we study evaporation energetics kinetics a chloride ion from liquid water by molecular dynamics simulations. As permeates interface, finger forms breaks at separation ≈ 2.8 nm Gibbs dividing surface. For larger separations 7 molecules are estimated to stay bound saturated vapor, as corroborated continuum dielectrics statistical mechanics models....

Most atomistic machine learning (ML) models rely on a locality ansatz and decompose the energy into sum of short-ranged, atom-centered contributions. This leads to clear limitations when trying describe problems that are dominated by long-range physical effects—most notably electrostatics. Many approaches have been proposed overcome these limitations, but efforts make them efficient widely available hampered need incorporate an ad hoc implementation methods treat interactions. We develop...

Despite the ubiquity of aqueous electrolytes, effect salt on water organization remains controversial. We introduce a nonlocal and nonlinear field theory for nanoscale polarization ions derive electrolyte dielectric response as function concentration to first order in loop expansion. By comparison with molecular dynamics simulations, we show that rising induces permittivity decrement Debye screening longitudinal susceptibility but leaves structure remarkably unchanged.

The dielectric constant and the viscosity of water at interface hydrophilic surfaces differ from their bulk values, it has been proposed that deviation is caused by strong electric field high ion concentration in interfacial layer. We calculate dependence electrolytes on salt concentration. Incorporating field-dependent extended Poisson–Boltzmann Stokes equations, we electro-osmotic mobility. compare results to literature experimental data explicit molecular dynamics simulations...

Biological and technological processes that involve liquids under negative pressure are vulnerable to the formation of cavities. Maximal pressures found in plants around <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mo>−</mml:mo></mml:math> 100 bar, even though cavitation pure bulk water only occurs at much more on relevant timescales. Here, we investigate influence small solutes lipid bilayers, both constituents all biological liquids, cavities pressures....

Although conceptually simple, the air-water interface displays rich behavior and is subject to intense experimental theoretical investigations. Different definitions of electrostatic surface potential as well different calculation methods, each relevant for distinct scenarios, lead widely varying magnitudes sometimes even signs. Based on quantum-chemical density-functional-theory molecular dynamics (DFT-MD) simulations, potentials are evaluated compared force-field (FF) MD simulations. As...

<ns7:p>Easy-to-use libraries such as scikit-learn have accelerated the adoption and application of machine learning (ML) workflows data-driven methods. While many algorithms implemented in these originated specific scientific fields, they gained popularity part because their generalisability across multiple domains. Over past two decades, researchers chemical materials science community put forward general-purpose The deployment methods into other domains, however, is often burdensome due to...

<ns3:p>Easy-to-use libraries such as scikit-learn have accelerated the adoption and application of machine learning (ML) workflows data-driven methods. While many algorithms implemented in these originated specific scientific fields, they gained popularity part because their generalisability across multiple domains. Over past two decades, researchers chemical materials science community put forward general-purpose The deployment methods into other domains, however, is often burdensome due to...

The influence of the co-solutes TMAO, urea, and NaCl on hydration repulsion between lipid membranes is investigated in a combined experimental/simulation approach.

Porphyrin molecules are particularly interesting candidates for spintronic applications due to their bonding flexibility, which allows modify properties substantially by the addition or transformation of ligands. Here, we investigate electronic and magnetic cobalt octaethylporphyrin (CoOEP), deposited on copper substrates with two distinct crystallographic surface orientations, Cu(100) Cu(111), X-ray absorption spectroscopy (XAS) circular dichroism (XMCD). A significant moment is present in...

Using classical molecular dynamics simulations, we investigate the dielectric properties at interfaces of water with graphene, graphite, hexane, and vapor. For compare metallic nonmetallic versions. At vapor-liquid hexane-water interfaces, laterally averaged profiles are significantly broadened due to interfacial roughness only slightly anisotropic. In contrast, rigid graphene surface, strongly anisotropic perpendicular profile exhibits pronounced oscillations sign changes. The excess,...

Solvent-implicit Monte Carlo (MC) simulations and mean-field theory are used to predict activity coefficients excess interfacial tensions for NaF, NaCl, NaI, KF, KCl, KI solutions in good agreement with experimental data over the entire experimentally available concentration range. The effective ionic diameters of solvent-implicit simulation model obtained by fits coefficient data. at high salt concentrations only reproduced if ion-specific concentration-dependent decrement dielectric...

The widespread application of machine learning (ML) to the chemical sciences is making it very important understand how ML models learn correlate structures with their properties, and what can be done improve training efficiency whilst guaranteeing interpretability transferability. In this work, we demonstrate wide utility prediction rigidities, a family metrics derived from loss function, in understanding robustness model predictions. We show that rigidities allow assessment not only at...

Water at negative pressures can remain in a metastable state for surprisingly long time before it reaches equilibrium by cavitation, i.e. the formation of vapor bubbles. The wide spread experimentally measured cavitation depending on water purity, surface contact angle and quality implicates relevance bulk, surfaces defects different systems. We formulate kinetic model that includes all three pathways determine needed nucleation attempt frequencies from atomistic molecular dynamics...