Abstract:The electrostatic part of the solvation energy has been studied by using extended Debye-Hückel (DH) theories. Specifically, our molecular Debye-Hückel theory [J. Chem. Phys. 2011, 135, 104104] and its simplified version, an energy-scaled Debye-Hückel theory, were applied to electrolytes with strong electrostatic coupling. Our theories provide a practical methodology for calculating the electrostatic solvation free energies, and the accuracy was verified for atomic and diatomic charged solutes.
“…Our MDH theory is applicable to the solutes with general geometry and charge density and has been tested for several systems. [25][26][27][28] With the above excess properties, it is possible to evaluate other thermodynamic properties of an electrolyte solution. The averaged excess internal energy per particle is…”
Section: F Electrostatic Contributions To Thermodynamic Properties: IImentioning
confidence: 99%
“…Note that χ(k) in most case is not analytically known, an empirical function χ(k) = a 0 k 2 k 4 + (a 1 k 2 − a 2 )Cos(kb) + a 3 Sin(kb) + a 2 can be used to fit the response function χ(k), and then the pole k = ik n can be determined by solving k 4 + (a 1 k 2 a 2 )Cos(kb) + a 3 Sin(kb) + a 2 = 0 numerically. 27,28 (2) The hard sphere contribution to the charge density ρ hs j (k) = n i q i x i h hs ij (k) can be evaluated using the analytical correlation function h hs ij (k) from the Percus-Yevick (PY) theory or other integral equation theory for hard sphere mixtures, 15 and then the cumulate charge Q hs j ≡ ∫ ρ hs j (r)4πr 2 dr and the electric potential ψ hs j ≡ ∫ ρ hs j (r) r 4πr 2 dr can be determined. The parameters ρ hs e and a d of the effective surface charge are evaluated by ρ hs e = (ψ hs j ) 2 /(4πQ hs j ) and a d = Q hs j /ψ hs j .…”
Section: G Prescriptions To Determine the Linear Coefficient {C As mentioning
confidence: 99%
“…Such a prescription has been applied successfully to the various ionic fluids. [25][26][27][28] In this contribution, we extend the MDH theory to the size asymmetric case, so that the cation and anion of the electrolyte solutions can have different sizes. It is known that the size asymmetry leads to a border zone around a solute ion, where the charge density is nonzero even for a neutral solute.…”
A molecular Debye-Hückel theory for electrolyte solutions with size asymmetry is developed, where the dielectric response of an electrolyte solution is described by a linear combination of Debye-Hückel-like response modes. As the size asymmetry of an electrolyte solution leads to a charge imbalanced border zone around a solute, the dielectric response to the solute is characterized by two types of charge sources, namely, a bare solute charge and a charge distribution due to size asymmetry. These two kinds of charge sources are screened by the solvent differently, our theory presents a method to calculate the mean electric potential as well as the electrostatic contributions to thermodynamic properties. The theory has been successfully applied to binary as well as multi-component primitive models of electrolyte solutions.
“…Our MDH theory is applicable to the solutes with general geometry and charge density and has been tested for several systems. [25][26][27][28] With the above excess properties, it is possible to evaluate other thermodynamic properties of an electrolyte solution. The averaged excess internal energy per particle is…”
Section: F Electrostatic Contributions To Thermodynamic Properties: IImentioning
confidence: 99%
“…Note that χ(k) in most case is not analytically known, an empirical function χ(k) = a 0 k 2 k 4 + (a 1 k 2 − a 2 )Cos(kb) + a 3 Sin(kb) + a 2 can be used to fit the response function χ(k), and then the pole k = ik n can be determined by solving k 4 + (a 1 k 2 a 2 )Cos(kb) + a 3 Sin(kb) + a 2 = 0 numerically. 27,28 (2) The hard sphere contribution to the charge density ρ hs j (k) = n i q i x i h hs ij (k) can be evaluated using the analytical correlation function h hs ij (k) from the Percus-Yevick (PY) theory or other integral equation theory for hard sphere mixtures, 15 and then the cumulate charge Q hs j ≡ ∫ ρ hs j (r)4πr 2 dr and the electric potential ψ hs j ≡ ∫ ρ hs j (r) r 4πr 2 dr can be determined. The parameters ρ hs e and a d of the effective surface charge are evaluated by ρ hs e = (ψ hs j ) 2 /(4πQ hs j ) and a d = Q hs j /ψ hs j .…”
Section: G Prescriptions To Determine the Linear Coefficient {C As mentioning
confidence: 99%
“…Such a prescription has been applied successfully to the various ionic fluids. [25][26][27][28] In this contribution, we extend the MDH theory to the size asymmetric case, so that the cation and anion of the electrolyte solutions can have different sizes. It is known that the size asymmetry leads to a border zone around a solute ion, where the charge density is nonzero even for a neutral solute.…”
A molecular Debye-Hückel theory for electrolyte solutions with size asymmetry is developed, where the dielectric response of an electrolyte solution is described by a linear combination of Debye-Hückel-like response modes. As the size asymmetry of an electrolyte solution leads to a charge imbalanced border zone around a solute, the dielectric response to the solute is characterized by two types of charge sources, namely, a bare solute charge and a charge distribution due to size asymmetry. These two kinds of charge sources are screened by the solvent differently, our theory presents a method to calculate the mean electric potential as well as the electrostatic contributions to thermodynamic properties. The theory has been successfully applied to binary as well as multi-component primitive models of electrolyte solutions.
“…72–80 Given its importance, researchers continuously focus on developing more accurate molecular models and exploring more powerful tools in simulations of ionic solutions. 81–88 The electrolyte of sodium chloride (NaCl), one of the most common salts, has been a target in many such simulation efforts. 89–92 However some basic properties of the NaCl electrolyte, such as the molality-dependent chemical potential and solubility, are hard to simulate accurately.…”
Solvent-mediated electrostatic interactions were well recognized to be important in the structure and function of molecular systems. Ionic interaction is an important component in electrostatic interactions, especially in highly charged molecules, such as nucleic acids. Here we focus on the quality of the widely used PBSA continuum models in modeling ionic interactions by comparing with both explicit solvent simulations and experiment. In this work, the molality-dependent chemical potentials for sodium chloride (NaCl) electrolyte were first simulated in the SPC/E explicit solvent. Our high-quality simulation agrees well with both previous study and experiment. Given the free energy simulations in SPC/E as the benchmark, we used the same sets of snapshots collected in the SPC/E solvent model for PBSA free energy calculations in the hope to achieve the maximum consistency between the two solvent models. Our comparative analysis shows that the molality-dependent chemical potentials of NaCl were reproduced well with both linear PB and nonlinear PB methods, though nonlinear PB agrees better with SPC/E and experiment. Our free energy simulations also show that the presence of salt increases the hydrophobic effect in a nonlinear fashion, in qualitative agreement with previous theoretical studies of Onsager and Samaras. However, the lack of molality-dependency in the non-electrostatics continuum models dramatically reduces the overall quality of PBSA methods in modeling salt-dependent energetics. These analyses points to further improvements needed for more robust modeling of solvent-mediate interactions by the continuum solvation frameworks.
“…In recent years, there have been extensive studies on the theory of dense fluids with Coulomb interactions. [16][17][18][19][20][21][22][23][24][25][26][27] Due to the universality of Coulomb interactions, one may expect that there are common properties shared by ionic fluids and polar fluids. As demonstrated by Kjellander and coworkers in the dressed ion theory 22,23 and the dressed molecule theory, 24 the Poisson equation for the electric potential of a solute in a solvent can always be reformulated as a linearized Debye-Hückel (DH)-like theory by an exact charge renormalization process.…”
A dielectric response theory of solvation beyond the conventional Born model for polar fluids is presented. The dielectric response of a polar fluid is described by a Born response mode and a linear combination of Debye-Hückel-like response modes that capture the nonlocal response of polar fluids. The Born mode is characterized by a bulk dielectric constant, while a Debye-Hückel mode is characterized by its corresponding Debye screening length. Both the bulk dielectric constant and the Debye screening lengths are determined from the bulk dielectric function of the polar fluid. The linear combination coefficients of the response modes are evaluated in a self-consistent way and can be used to evaluate the electrostatic contribution to the thermodynamic properties of a polar fluid. Our theory is applied to a dipolar hard sphere fluid as well as interaction site models of polar fluids such as water, where the electrostatic contribution to their thermodynamic properties can be obtained accurately.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.