<i>Ab Initio</i> Force Fields for Imidazolium-Based Ionic Liquids

McDaniel, Jesse G.; Choi, Eunsong; Son, Chang Yun; Schmidt, J. R.; Yethiraj, Arun

doi:10.1021/acs.jpcb.6b05328

Cited by 78 publications

(133 citation statements)

References 110 publications

Supporting

Mentioning

121

Contrasting

Order By: Relevance

“…It should be noted that the short‐range terms produced by common force fields may have little in common with the SAPT(DFT) reference values even though total interaction energies at equilibrium distances are similar . Various forms of the short‐range terms have been proposed in the literature, with their adjustable parameters fitted to SAPT or SAPT(DFT) data, and earlier ab initio force fields for specific systems were later generalized to provide force fields that are transferable at least within a class of similar compounds . In the last few years, an enhanced force‐field description of short‐range interactions has been brought about by considering the asymptotic form of the intermolecular density overlap and using novel algorithms to partition molecular density into atomic contributions .…”

Section: The Sapt Formalismmentioning

confidence: 99%

Recent developments in symmetry‐adapted perturbation theory

Patkowski

2019

WIREs Comput Mol Sci

149

144

View full text Add to dashboard Cite

Symmetry-adapted perturbation theory (SAPT) is a well-established method to compute accurate intermolecular interaction energies in terms of physical effects such as electrostatics, induction (polarization), dispersion, and exchange. With many theory levels and variants, and several computer implementations available, closed-shell SAPT has been applied to produce numerous intermolecular potential energy surfaces for complexes of experimental interest, and to elucidate the interactions in various complexes relevant to catalysis, organic synthesis, and biochemistry. In contrast, the development of SAPT for general open-shell complexes is still a work in progress. In the last decade, new developments from several research groups, including the author's, have greatly enhanced the capabilities of SAPT. The new and emerging approaches are designed to make SAPT more widely applicable (including interactions involving multireference systems, complexes in arbitrary spin states, and intramolecular noncovalent interactions), more accurate (enhanced description of intramolecular correlation, a better account of exchange effects, relativistic SAPT, and explicitly correlated SAPT), and more efficient (enhanced density-fitted implementations, linearscaling variants, empirical dispersion, and an implementation on graphics processing units).The new developments open up avenues for SAPT applications to an unprecedented variety of weakly interacting complexes.

show abstract

Section: The Sapt Formalismmentioning

confidence: 99%

Recent developments in symmetry‐adapted perturbation theory

Patkowski

2019

WIREs Comput Mol Sci

149

144

View full text Add to dashboard Cite

show abstract

“…Ion association varies dramatically with concentration and depends on the ion-pair interaction energies, which are not accurately described by nonpolarizable force fields as is well-documented within the context of vaporization enthalpy prediction. [58][59][60][61] Additionally, so-called "scaled charge" force fields severely underestimate the cohesive energy of ionic liquids, and do not accurately reproduce ion association trends for varying dielectric solvents. 57 To overcome such limitations, in this work we utilize ab initio, polarizable force fields, based on symmetry-adapted perturbation theory (SAPT), as developed previously.…”

Section: -40mentioning

confidence: 99%

Ion Correlation and Collective Dynamics in BMIM/BF₄-Based Organic Electrolytes: From Dilute Solutions to the Ionic Liquid Limit

2018

Self Cite

View full text Add to dashboard Cite

Quantifying ion association and collective dynamical processes in organic electrolytes is essential for fundamental property interpretation and optimization for electrochemical applications. The extent of ion correlation depends on both the ion concentration and dielectric strength of the solvent; ions may be largely uncorrelated in sufficiently high dielectric solvents at low concentration, but properties of concentrated electrolytes are dictated by correlated and collective ion processes. In this work, we utilize molecular dynamics simulations to characterize ion association and collective ion dynamics in organic electrolytes composed of binary mixtures of 1-butyl-3-] and 1,2-dichloroethane, acetone, acetonitrile, and water solvents. We illustrate different physical regimes of characteristically distinct ion correlation for the systematic range of electrolyte concentrations and solvent dielectric strengths. Dilute electrolytes composed of low-dielectric solvents exhibit significant counterion correlation in the form of ion-pairing and clustering driven by both weak screening and relatively low solvation energies. This regime is characterized by enhanced ion coordination numbers and near equality of cation and anion diffusion coefficients, despite the significantly different ion sizes. In contrast, ion correlation in highly concentrated electrolytes is dominated by the anti-correlated motion of both like-charge and opposite-charge ions, approaching neat ionic liquid behavior. We show that the cross-over of these correlation regimes is clearly illuminated by quantifying the fractional self and distinct contributions to the net ionic conductivity. For organic electrolytes composed of low-dielectric solvents, we conclude that significant ion correlation exists at all concentrations, but the nature of the correlation changes markedly from the dilute electrolyte to the pure ionic liquid limit.

show abstract

“…Accurate atomistic force fields must be further developed and validated for a much larger range of ionic compounds. Many force fields have been published, especially for imidazoliumbased ILs [24,46,52,58,61,62,65,66]. Lopes and Padua have produced a large set of force field parameters based on OPLS format [52,67,69], and several other groups have been active in developing force fields as well.…”

Section: Discussionmentioning

confidence: 99%

4. Multigranular modeling of ionic liquids

Wang¹,

Sarman²,

Laaksonen³

et al. 2019

Ionic Liquids

View full text Add to dashboard Cite

Ionic liquids (ILs) are a special category of molten salts with melting points near ambient temperatures (or by convention below 100°C). Owing to their numerous valuable physicochemical properties as bulk liquids, solvents, at surfaces and in confined environments, ILs have attracted increasing attention in both academic and industrial communities in a variety of application areas involving physics, chemistry, material science and engineering. Due to their nearly limitless number of combinations of cation-anion pairs and mixtures with cosolvents, a molecular level understanding of their hierarchical structures and dynamics, requiring strategies to connect several length and time scales, is of crucial significance for rational design of ILs with desired properties, and thereafter refining their functional performance in applications. As an invaluable compliment to experiments from synthesis to characterization, computational modeling and simulations have significantly increased our understanding on how physicochemical and structural properties of ILs can be controlled by their underlying chemical and molecular structures. In this chapter, we will give examples from our own modeling work based on selected IL systems, with focus on imidazolium-based and tetraalkylphosphonium-orthoborate ILs, studied at several spatio-temporal scales in different environments and with particular attention to applications of high technological interest. We start by describing studies performed using ab initio methods on force field development for tetraalkylphosphonium-orthoborate ILs, and computational studies on thermal decomposition of these ILs. The delicate interplay between hydrogen bonding and π-type interactions in an imidazolium-orthoborate IL was studied by performing ab initio molecular dynamics simulations. On the atomistic level, atomistic simulations were performed with constructed force field parameters to study intrinsic molecular interactions between residual water molecules and tetraalkylphosphoniumorthoborate ionic species. For a typical trihexyltetradecylphosphonium bis(oxalato) borate IL at varied concentrations, microstructures and dynamics were systematically analyzed as water concentration increases. The liquid viscosities of typical trihexyltetradecylphosphonium-based ILs were estimated through equilibrium atomistic simulations using Green-Kubo relation with charge scaling factors on ionic species.Additionally, atomistic simulations were combined with X-ray scattering experiments to investigate phase behavior and ionic structures in IL mixtures with varied concentrations. Peculiar features of X-ray scattering spectra of IL mixtures with organic solvent are also discussed with an example dealing with ethyl ammonium nitrate and acetonitrile mixtures. On the mesoscopic level, a united-atom model for trihexyltetradecylphosphonium cation and coarse-grained models for butylmethy-limidazolium hexafluorophosphate were proposed, and effective interactions between coarse-grained beads were validated against experimental...

show abstract

Ab Initio Force Fields for Imidazolium-Based Ionic Liquids

Cited by 78 publications

References 110 publications

Recent developments in symmetry‐adapted perturbation theory

Recent developments in symmetry‐adapted perturbation theory

Ion Correlation and Collective Dynamics in BMIM/BF₄-Based Organic Electrolytes: From Dilute Solutions to the Ionic Liquid Limit

4. Multigranular modeling of ionic liquids

Contact Info

Product

Resources

About

Ab Initio Force Fields for Imidazolium-Based Ionic Liquids

Cited by 78 publications

References 110 publications

Recent developments in symmetry‐adapted perturbation theory

Recent developments in symmetry‐adapted perturbation theory

Ion Correlation and Collective Dynamics in BMIM/BF4-Based Organic Electrolytes: From Dilute Solutions to the Ionic Liquid Limit

4. Multigranular modeling of ionic liquids

Contact Info

Product

Resources

About

Ion Correlation and Collective Dynamics in BMIM/BF₄-Based Organic Electrolytes: From Dilute Solutions to the Ionic Liquid Limit