We present a molecular-dynamics study of the self-dynamics water molecules in deeply supercooled liquid states. find that decay single-particle dynamics correlation functions is characterized by fast initial relaxation toward plateau and region self-similar dynamics, followed at late times stretched exponential decay. interpret such results framework mode-coupling theory for liquids. relate apparent anomalies transport coefficients on lowering temperature to formation cages associated slow...

We perform long molecular dynamics simulations of liquid water in normal and supercooled states for times up to 50 ns. observe the onset a cage effect at 0.25 ps followed by diffusion much longer time. The constant has power-law temperature dependence. long-time single-particle is dominated two-step process, beta alpha relaxations, familiar mode-coupling theory simple liquids. Over length scales comparable size decay characterized relaxation rate having ${q}^{2}$ $q$ crossover close kinetic...

We present here molecular dynamics simulations of deeply supercooled SPC/E water confined in a cylindrical pore MCM-41 silica material. By layer analysis the tag particle density correlators, we are able to extract α-relaxation time mobile portion water. This relaxation is same as what can be extracted from neutron scattering experiments. From examination temperature-dependent behavior and dynamic susceptibility, locate crossover at T = (215 ± 5) K corresponding peak specific heat, agreement...

In order to investigate the cryoprotective mechanism of trehalose on proteins, we use molecular dynamics computer simulations study microscopic water upon cooling in an aqueous solution lysozyme and trehalose. We find that presence causes global retardation water. Comparing solutions with/without trehalose, observe hydration layers close protein is dramatically slower when present system. also analyze structure around molecules form a cage surrounding contains very slow molecules. conclude...

An exhaustive study by molecular dynamics has been performed to analyze the factors that enhance precision of technique direct coexistence for a system ice and liquid water. The analyzed are stochastic nature method, finite size effects, influence initial configuration used. results obtained show estimates through is markedly affected effects size, requiring systems with large number molecules reduce error bar melting point. This increase in causes an simulation time, but estimate point...

We present a Molecular Dynamics study of the single particle dynamics supercooled water confined in silica pore. Two dynamical regimes are found: close to hydrophilic substrate molecules below Mode Coupling crossover temperature, $T_C$, already at ambient temperature. The closer center pore (free water) approaches upon supercooling $T_C$ as predicted by Theories. For free temperature and exponent $\gamma$ extracted from power-law fits both diffusion coefficient relaxation time late $\alpha$ region.

Single particle dynamics of water confined in a nanopore is studied through computer molecular dynamics. The pore modeled to represent the average properties Vycor glass. Dynamics analyzed at different hydration levels and upon supercooling. At all temperatures investigated layering effect observed due strong hydrophilicity substrate. time density correlators show, already ambient temperature, deviations from Debye stretched exponential behavior. Both on decreasing level supercooling we find...

A molecular-dynamics simulation of extended simple point charge water in a time interval 1 fs to 50 ns has been performed study the single-particle dynamics at supercooled temperatures. In spite fact that upon supercooling progressively evolves into more open structure locally, is nevertheless shown be dominated by so-called cage effect experienced test particle. The slow structural relaxation low temperatures leads phenomenon can only completely studied following trajectories nanosecond...

A Molecular Dynamics simulation of the microscopic structure water confined in a silica pore is presented. single cavity glass has been modeled as to reproduce main features pores real Vycor glass. layer analysis site-site radial distribution functions evidence presence two subsets molecules with different structure. Molecules which reside inner layer, close center pore, have same bulk but at temperature 30 K higher. On contrary outer substrate, strongly influenced by water-substrate...

In this paper we investigate the possibility to detect hypothesized liquid-liquid critical point of water in supercooled aqueous solutions salts. Molecular dynamics computer simulations are conducted on bulk TIP4P and an solution sodium chloride water, with concentration c=0.67 mol/kg. The is found both solution. Its position thermodynamic plane shifts higher temperature lower pressure for Comparison available experimental data allowed us produce phase diagrams as measurable experiments....

We study with the method of molecular dynamics simulation structural properties aqueous solutions NaCl, KCl and KF salts at ambient conditions upon supercooling constant pressure. The calculations are performed increasing concentration salt starting from c = 0.67 mol kg−1 up to 3.96 kg−1. investigate modifications hydration shells changes in water structure induced by presence ions. oxygen–oxygen is strongly dependent on ionic while it almost independent cation. hydrogen bonding preserved...

The Cl⁻ ion included in the lattice always substitutes not one but two water molecules favoring ice conduction.

We study by molecular dynamics simulations supercooled water with the TIP4P/2005 potential. This model is able to predict many properties of in a large range thermodynamic space agreement experiments. explore dynamical behavior and, particular, self intermediate scattering function oxygen atoms. find that structural relaxation mild supercooling Mode Coupling Theory (MCT). The ideal MCT crossover takes place at decreasing temperature increasing density. Deviations from are found upon further...

We analyze a set of 10 M-step molecular dynamics (MD) data low-temperature SPC/E model water with phenomenological analytical model. The motivation is twofold: to extract various k-dependent physical parameters associated the single-particle or self-intermediate scattering functions (SISFs) at deeply supercooled temperature and apply this analyses new high resolution quasielastic neutron presented elsewhere. SISF center mass computed from MD show clearly time-separated two-step relaxations...

We present a finite-size scaling study of the liquid-liquid critical point in Jagla model, prototype model for liquids that same thermodynamic anomalies which characterize liquid water. Performing successive umbrella sampling grand canonical Monte Carlo simulations, we evaluate an accurate density states different system sizes and determine size-dependent parameters. Extrapolation to infinite size provides estimates bulk values this model. The allows us establish fluctuations are consistent...

We present the results of molecular dynamics simulations on water confined in a silica pore 15 Å modelled to mimic MCM-41 structure. focus dynamical properties for different hydration levels pore. Density profiles show well-defined double-layer structure close surface. From analysis layers we find that molecules substrate an anomalous diffusion which is connected behaviour residence time distribution. The interaction with induces temporal disorder. As consequence strong deviations are found...

We consider one of the most used model for water, rigid four site TIP4P potential, and we study by molecular dynamics simulation dynamical properties liquid upon supercooling. In previous studies thermodynamics a liquid-liquid critical point (LLCP) located at end coexistence between low density (LDL) high (HDL) water was found. present here analysis self intermediate scattering functions in large range temperatures densities show that structural relaxation region mild supercooling is...

We perform molecular dynamics simulations in order to study thermodynamics and the structure of supercooled aqueous solutions lithium chloride (LiCl) at concentrations c = 0.678 2.034 mol/kg. model solvent using TIP4P/2005 potential ions Madrid-2019 force field, a field particularly suited for studying this solution. find that, mol/kg, behavior equation state, studied P–T plane, indicates presence liquid–liquid phase transition, similar what was previously found bulk water. estimate position...