The Solid-Liquid Interface: Theory and Computer Simulations

1985 ◽  
Vol 63 ◽  
Author(s):  
B. B. Laird ◽  
A. D. J. Haymet
Keyword(s):  
Computer Simulations ◽  
Density Functional ◽  
Dynamic Properties ◽  
Computer Experiments ◽  
Liquid Interface ◽  
Liquid Interfaces ◽  
Functional Theory ◽  
Interface Theory ◽  
Solid Liquid Interface ◽  
Solid Liquid

ABSTRACTWe present the results of computer simulations of body centered cubic (bcc)/melt interfaces, with particular emphasis on the “width” of the interface. Both static and dynamic properties of single crystal/liquid interfaces are examined. The implications for crystal growth near equilibrium are discussed. The results of these computer “experiments” are compared with an extended density functional theory of the solid-liquid interface.

scholarly journals The interface of SrTiO 3 and H 2 O from density functional theory molecular dynamics

2016 ◽  
Vol 472 (2193) ◽  
pp. 20160293 ◽  
Author(s):  
E. Holmström ◽  
P. Spijker ◽  
A. S. Foster
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Density Functional ◽  
Liquid Interface ◽  
Strong Suppression ◽  
Electronic Density ◽  
Functional Theory ◽  
Degree Of Dissociation ◽  
Solid Liquid Interface ◽  
Solid Liquid

We use dispersion-corrected density functional theory molecular dynamics simulations to predict the ionic, electronic and vibrational properties of the SrTiO 3 /H 2 O solid–liquid interface. Approximately 50% of surface oxygens on the planar SrO termination are hydroxylated at all studied levels of water coverage, the corresponding number being 15% for the planar TiO 2 termination and 5% on the stepped TiO 2 -terminated surface. The lateral ordering of the hydration structure is largely controlled by covalent-like surface cation to H 2 O bonding and surface corrugation. We find a featureless electronic density of states in and around the band gap energy region at the solid–liquid interface. The vibrational spectrum indicates redshifting of the O–H stretching band due to surface-to-liquid hydrogen bonding and blueshifting due to high-frequency stretching vibrations of OH fragments within the liquid, as well as strong suppression of the OH stretching band on the stepped surface. We find highly varying rates of proton transfer above different SrTiO 3 surfaces, owing to differences in hydrogen bond strength and the degree of dissociation of incident water. Trends in proton dynamics and the mode of H 2 O adsorption among studied surfaces can be explained by the differential ionicity of the Ti–O and Sr–O bonds in the SrTiO 3 crystal.

scholarly journals Grand-Canonical Approach to Density Functional Theory of Electrocatalytic Systems: Thermodynamics of Solid-Liquid Interfaces at Constant Ion and Electrode Potentials

2018 ◽  
Author(s):  
Marko Melander ◽  
Mikael Kuisma ◽  
Thorbjørn Christensen ◽  
Karoliina Honkala
Keyword(s):  
Density Functional ◽  
Canonical Ensemble ◽  
Coarse Graining ◽  
Grand Canonical Ensemble ◽  
Liquid Interfaces ◽  
Functional Theory ◽  
Electrode Potentials ◽  
Solid Liquid ◽  
Electrochemical Interfaces ◽  
Grand Canonical

Properties of solid-liquid interfaces are of immense importance for electrocatalytic and electrochemical systems but modelling such interfaces at the atomic level presents a serious challenge and approaches beyond standard methodologies are needed. An atomistic computational scheme needs treat at least part of the system quantum mechanically to include adsorption and reactions while the entire system is in thermal equilibrium. The experimentally relevant macroscopic control variables are temperature, electrode potential, choice of the solvent and ions and these need to be explicitly included in the computational model as well; this calls for an thermodynamic ensemble with fixed ion and electrode potentials. In this work a general framework within density functional theory with fixed electron and ion chemical potentials in the grand canonical ensemble is established for modelling electrocatalytic and electrochemical interfaces. Starting from a fully quantum mechanical description of nuclei and electrons, a systematic coarse-graining is employed to establish various computational schemes including i) the combination of classical and electronic density functional theories within the grand canonical ensemble and ii) on the simplest level a chemically and physically sound way to obtain the (modified) Poisson-Boltzmann (mPB) implicit solvent model. The detailed and rigorous derivation clearly establishes which approximations are needed for coarse-graining as well as highlights which details and interactions are omitted in vein of computational feasibility. The transparent approximations also allow removing some the constraints and coarse-graining if needed. We implement various mPB models in the GPAW code and test their capabilities to model capacitance of electrochemical interfaces as well as study different approaches for modelling partly periodic charged systems. Our rigorous and well-defined DFT coarse-graining scheme to continuum electrolytes highlights the inadequacy of current linear dielectric models for treating properties of the electrochemical interface.<br><br>

scholarly journals Grand-Canonical Approach to Density Functional Theory of Electrocatalytic Systems: Thermodynamics of Solid-Liquid Interfaces at Constant Ion and Electrode Potentials

2018 ◽  
Author(s):  
Marko Melander ◽  
Mikael Kuisma ◽  
Thorbjørn Christensen ◽  
Karoliina Honkala
Keyword(s):  
Density Functional ◽  
Canonical Ensemble ◽  
Coarse Graining ◽  
Grand Canonical Ensemble ◽  
Liquid Interfaces ◽  
Functional Theory ◽  
Electrode Potentials ◽  
Solid Liquid ◽  
Electrochemical Interfaces ◽  
Grand Canonical

Properties of solid-liquid interfaces are of immense importance for electrocatalytic and electrochemical systems but modelling such interfaces at the atomic level presents a serious challenge and approaches beyond standard methodologies are needed. An atomistic computational scheme needs treat at least part of the system quantum mechanically to include adsorption and reactions while the entire system is in thermal equilibrium. The experimentally relevant macroscopic control variables are temperature, electrode potential, choice of the solvent and ions and these need to be explicitly included in the computational model as well; this calls for an thermodynamic ensemble with fixed ion and electrode potentials. In this work a general framework within density functional theory with fixed electron and ion chemical potentials in the grand canonical ensemble is established for modelling electrocatalytic and electrochemical interfaces. Starting from a fully quantum mechanical description of nuclei and electrons, a systematic coarse-graining is employed to establish various computational schemes including i) the combination of classical and electronic density functional theories within the grand canonical ensemble and ii) on the simplest level a chemically and physically sound way to obtain the (modified) Poisson-Boltzmann (mPB) implicit solvent model. The detailed and rigorous derivation clearly establishes which approximations are needed for coarse-graining as well as highlights which details and interactions are omitted in vein of computational feasibility. The transparent approximations also allow removing some the constraints and coarse-graining if needed. We implement various mPB models in the GPAW code and test their capabilities to model capacitance of electrochemical interfaces as well as study different approaches for modelling partly periodic charged systems. Our rigorous and well-defined DFT coarse-graining scheme to continuum electrolytes highlights the inadequacy of current linear dielectric models for treating properties of the electrochemical interface.<br><br>

scholarly journals Shining light on the solid–liquid interface: in situ/operando monitoring of surface catalysis

2020 ◽  
Vol 10 (16) ◽  
pp. 5362-5385
Author(s):  
Leila Negahdar ◽  
Christopher M. A. Parlett ◽  
Mark A. Isaacs ◽  
Andrew M. Beale ◽  
Karen Wilson ◽  
...  
Keyword(s):  
Liquid Interface ◽  
Solid Catalyst ◽  
Chemical Transformations ◽  
Liquid Interfaces ◽  
Surface Catalysis ◽  
Catalytically Active ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Insight Into

Many industrially important chemical transformations occur at the interface between a solid catalyst and liquid reactants. In situ and operando spectroscopies offer unique insight into the reactivity of such catalytically active solid–liquid interfaces.

scholarly journals Vapor−Liquid Interface of the Lennard-Jones Truncated and Shifted Fluid: Comparison of Molecular Simulation, Density Gradient Theory, and Density Functional Theory

2021 ◽  
Author(s):  
Simon Stephan ◽  
Jinlu Liu ◽  
Kai Langenbach ◽  
Walter G. Chapman ◽  
Hans Hasse
Keyword(s):  
Density Functional Theory ◽  
Density Gradient ◽  
Density Functional ◽  
Computer Experiments ◽  
Liquid Interface ◽  
Gradient Theory ◽  
Functional Theory ◽  
Lennard Jones ◽  
Density Gradient Theory ◽  
Vapor Liquid

The vapor-liquid interface of the Lennard-Jones truncated and shifted (LTJS) fluid with a cut-off radius of 2.5 σ is investigated for temperatures covering the range between the triple point and the critical point. Three different approaches to model the vapor-liquid interface are used: molecular dynamics (MD) simulations, density gradient theory (DGT) and density functional theory (DFT). The surface tension, pressure and density profiles, including the oscillatory layering structure of the fluid at the interface, are investigated. The PeTS (Perturbed truncated and shifted) equation of state and PeTS-i functional, based on perturbation theory, are used to calculate the Helmholtz free energy in the DGT and DFT approach. They are consistent with the LJTS force field model. Overall, both DGT and DFT describe the results from computer experiments well. An oscillatory layering structure is found in MD and DFT.

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