Communication: Dielectric properties of condensed systems composed of fragments

Pan, Ding; Govoni, Marco; Galli, Giulia

doi:10.1063/1.5044636

Cited by 9 publications

(18 citation statements)

References 30 publications

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“…Besides enhancing the dipole moment, the TiO 2 surface also disrupts the isotropy of the polarizability tensor (α ij ) of the interfacial water. As shown in Figure b, the diagonal components of the polarizability differ one from the other for the water molecules adsorbed on the TiO 2 surface (first and second layers), at variance with what is found for bulk liquid water. , We can also see an overall increase of the polarizability of water in the second solvation layer (especially of the α bb component, where b is typically aligned with the anatase [010] direction for the second-layer molecules) relative to water in other layers. Detailed analysis indicates that this enhancement originates from configurations of the type shown in Figure d, which are also the configurations mainly responsible for the ice-like dynamics of water adsorbed on anatase (101).…”

supporting

confidence: 51%

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO₂

Andrade

Car

et al. 2018

J. Phys. Chem. Lett.

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The photocatalytic activity of TiO 2 for water splitting has been known for decades, yet the adsorption structure and hydrogen bonding of water at the interface with TiO 2 have remained controversial. We investigate the prototypical aqueous interface with anatase TiO 2 (101) using ab initio molecular dynamics (AIMD) with the strongly constrained and appropriately normed (SCAN) density functional, recently shown to provide an excellent description of the properties of bulk liquid water. We find that water forms a stable bilayer of intact molecules with ice-like dynamics and enhanced dipole moment and polarizability on the anatase surface. The orientational order and H-bond environment of interfacial water are reflected in the computed sum frequency generation (SFG) spectrum, which agrees well with recent measurements in the OH stretching frequency range (3000−3600 cm −1 ). Additional AIMD simulations for a model interface with 66% of dissociated water in the contact layer show that surface hydroxyls disrupt the order in the bilayer and lead to a much faster orientational dynamics of interfacial water. Nonetheless, the computed SFG spectrum for the hydroxylated surface also agrees with experiment, suggesting that SFG measurements in a wider frequency range would be necessary to unambiguously identify the character of interfacial water on anatase.

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confidence: 51%

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO₂

Andrade

Car

et al. 2018

J. Phys. Chem. Lett.

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“…We first summarize a general formulation recently introduced to obtain molecular polarizabilities in condensed phases using calculations based on density functional theory (DFT) 35 (see Figure 1). The electronic density of a solid cannot be straightforwardly partitioned into the sum of electronic densities of its constituents.…”

Section: Molecular Polarizabilitiesmentioning

confidence: 99%

“…In many studies, E env was approximated by dipole− induced-dipole (DID) electrostatic interactions, 38,40,51 while in recent developments this approximation was eliminated and all multipolar contributions were considered. 35 Since E is fixed (it is the external applied field), we only need to determine…”

Section: ■ Intrinsic Molecular Polarizabilitiesmentioning

confidence: 99%

“…32−34 The polarizabilities of gas phase molecules can be straightforwardly computed using several first-principles methods based on DFT. 35 However, polarizabilities in condensed phases are more challenging to define and compute, since all intermolecular interactions acting on a specific molecule need to be taken into account. In many instances, the Clausius−Mossotti (CM) equation 36 has been used to relate the average atomic or molecular polarizability, α, of building blocks to the system's electronic dielectric constant, which is related to the refractive index via the Lorentz− Lorentz equation.…”

Section: ■ Introductionmentioning

confidence: 99%

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Molecular Polarizabilities in Aqueous Systems from First-Principles

Rozsa

Galli

2021

J. Phys. Chem. B

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We discuss the results of first-principles calculations of molecular polarizabilities in condensed systems composed of well-defined building blocks, with a focus on water and simple aqueous solutions. We show that molecular polarizabilities are subtle fingerprints of structural changes induced in liquid water by the environment, e.g., the presence of ions and confined media, as well as by temperature and pressure. We also point out the importance of molecular polarizabilities in the calculation and interpretation of specific vibrational signatures of aqueous systems, notably Raman and sum-frequency generation spectra.

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“…In an effort to simplify the computational cost and to reach a better understanding of how the molecular components of a system interact with each other, our group, [28,29,33,39] as well as many others, [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] has looked into ways to represent properties (including response functions, polarizabilities, and other properties) of the total system as functions of subsystem quantities.…”

Section: Spectral Broadening and Observable Fluctuationsmentioning

confidence: 99%

Many‐body response of benzene at monolayer MoS₂: Van der Waals interactions and spectral broadening

Umerbekova

Pavanello

2020

Int J of Quantum Chemistry

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Models of surface enhancement of molecular electronic response properties are challenging for two reasons: (a) molecule-surface interactions require a simultaneous solution of the molecular and the surface dynamic response (a daunting task), and (b) when solving for the electronic structure of the combined molecule + surface system, it is not trivial to single out the particular physical effects responsible for enhancement. To tackle this problem, in this work, we apply a formally exact decomposition of the system's response function into subsystem contributions by using subsystem density functional theory (DFT), which grants access to dynamic polarizabilities and optical spectra. In order to access information about the interactions between the subsystems, we extend a previously developed subsystem-based adiabatic connection fluctuation-dissipation theorem of DFT to separate the additive from the nonadditive correlation energy and identify the nonadditive correlation as the van der Waals interactions. As an example, we choose benzene adsorbed on monolayer MoS 2. We isolate the contributions to benzene's dynamic response arising from the interaction with the surface, and for the first time, we evaluate the enhancements to the effectiveness of C 6 coefficients as a function of benzene-MoS 2 distance and adsorption site. We also quantify the spectral broadening of the benzene's electronic excited states due to their interaction with the surface. We find that the broadening has a similar decay law with the molecule-surface distance as the leading van der Waals interactions (ie, R −6) and that the surface enhancement of dispersion interactions between benzene molecules is less than 5% but is still large enough (0.5 kcal/mol) to likely play a role in the prediction of interface morphologies. K E Y W O R D S linear response, many body dispersion, TDDFT, van der Waals 1 | INTRODUCTION AND BACKGROUND The development of accurate models of materials' interfaces is a priority for materials science and engineering. [1,2] Interfaces are key regions in energy materials such as photovoltaics [3] and photocatalysts, [4] as well as in technological applications such as field-effect transistors. [5] Models must be accurate, in the sense that they need to at least reproduce the most basic of properties involved in the function of the material. These vary depending on the applications [6,7] ; however, properties such as the contact angle in a surface-water interface, [8] thermal transport in the material, [9] and the optical response [10] are among the ones widely sought after. An accurate model enables the rational design of materials, which

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Communication: Dielectric properties of condensed systems composed of fragments

Cited by 9 publications

References 30 publications

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO₂

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO₂

Molecular Polarizabilities in Aqueous Systems from First-Principles

Many‐body response of benzene at monolayer MoS₂: Van der Waals interactions and spectral broadening

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Communication: Dielectric properties of condensed systems composed of fragments

Cited by 9 publications

References 30 publications

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO2

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO2

Molecular Polarizabilities in Aqueous Systems from First-Principles

Many‐body response of benzene at monolayer MoS2: Van der Waals interactions and spectral broadening

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Product

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Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO₂

Structure, Polarization, and Sum Frequency Generation Spectrum of Interfacial Water on Anatase TiO₂

Many‐body response of benzene at monolayer MoS₂: Van der Waals interactions and spectral broadening