Aug 2026· Journal of Chemical Theory and Computation· Vol 22, pp. 8521 - 8530· 0 citations· 73 references
Medicine
Abstract
The performance of batteries is heavily influenced by the properties of their solvents, which play a crucial role in ion solvation, conductivity, and electrochemical stability. However, traditional force field models often fall short in accurately predicting these properties. This study investigates the potential of adaptive force matching (AFM) to predict a range of solvent-related properties using only electronic structure theory. To demonstrate this approach, we developed AFM models based on B3LYP-D3(BJ) for three common molecules present in battery solvents: dimethylamine (DMA), dimethyl carbonate (DMC), and tetrahydrofuran (THF). Our results reveal that AFM models significantly outperform traditional force fields, including OPLS-AA (CM1A), GAFF2, and GROMOS 54A7, in predicting key properties such as density, heat of vaporization, viscosity, diffusion constant, boiling temperature, and free energy of vaporization. Notably, the average percentage error of AFM models is approximately 13%, substantially lower than that of traditional force fields (21% for GAFF2, the best-performing empirical model). These findings underscore the promise of AFM in predicting physical properties of battery solvents, with far-reaching implications for chemistry, materials science, and related fields where accurate predictions are essential for understanding complex phenomena and designing innovative materials and systems.
Accurate prediction of solubility is crucial in various fields, including pharmaceuticals, environmental chemistry, and materials science. In this study, we demonstrate the application of Adaptive Force Matching (AFM) to predict the solubility of molecular liquids in water. By developing high-quality force fields using AFM, we accurately compute the free energy of vaporization and hydration, which are essential components for predicting solubility. Our results show that AFM models can reliably predict the solvation free energy of selected small molecules, exhibiting a deviation of <1.3 kJ/mol from experimental references for cyclohexene, isopentane, and n-butanol. Although a slightly larger error is observed for n-octanol, which was developed by borrowing AFM parameters from other molecules, the deviation remains comparable to commonly accepted chemical accuracy. This study highlights the potential of AFM as a powerful tool for predicting solubility, enabling the design and development of new materials and molecules with tailored properties.
Unknown authors· Journal of Chemical Physics· 0 citations
Ionic liquids are salts that exist in the liquid state at room temperature and exhibit high viscosity because of their strong electrostatic interactions. It was difficult to reproduce their viscosity by molecular dynamics simulations with conventional nonpolarizable force fields; however, recent development of force fields implementing electronic continuum correction (ECC), which accounts for polarizability, has enabled accurate predictions. Here, we present a regression-guided strategy to optimize scaling factors for ECC charges and Lennard-Jones parameters for monomeric (BMIM+, MOEMIM+) and oligomeric (IL22+, IL44+) imidazolium-based cations paired with TFSI– with united-atom models. The scaling factors were optimized to simultaneously reproduce experimental density and viscosity. To validate the strategy, we calculated the temperature dependence of density, diffusion coefficient, conductivity, and viscosity of BMIM–TFSI, achieving good agreements with experiments. Moreover, scaling factors optimized for MOEMIM+, which shares similar chemical structure and elemental compositions with IL22+ and IL44+, were found to be transferable to these compounds. Thus, this work not only provides a practical regression-guided workflow for selecting ECC-based united-atom force-field parameters but also suggests their transferability across chemically related ionic liquids.
Lithium metal batteries (LMBs) offer high energy density, but interfacial charge-transfer kinetics remain a bottleneck for high-rate operation. In this work, we construct a library of 12 ether solvents with systematic variations in symmetry and fluorination, confirming that molecular asymmetry is an important feature that results in enhanced Li+ redox kinetics and more stable solid electrolyte interphases on Li0. Furthermore, we developed a mechanistic understanding of the underlying process. We show that more tilted dipoles and lower moments of inertia strongly correlate with higher exchange current densities. Among the solvents in our study, the asymmetric F5MPE (1-methoxy-2-(2,2,3,3,3-pentafluoropropoxy) ethane) molecule, a previously unreported solvent molecule, enabled >170 stable cycles in high-rate Li||NMC full cells, outperforming the previously reported best single-salt-single-solvent ether solvent, F5DEE molecule. Overall, this work links molecular-level information with the behavior at electrochemical interfaces and provides an understanding of molecular design considerations for next-generation electrolytes tailored for high-power, fast-charging LMBs.
Il Rok Choi, Aditya Shah, Jeffrey Heo et al.· Journal of the American Chem...· 0 citations
In contrast to traditional lead-based perovskites, double perovskites are receiving considerable attention owing to their highly tunable photovoltaic performance and remarkable stability, which can be further enhanced through compositional engineering. We have theoretically investigated the structural, mechanical, dynamical, optical, and electronic properties of Cs2RbCoX6 (X = F, Cl, Br, and I) using first-principles calculations performed with VASP. The structural and mechanical stability of the investigated cubic structures was assessed using tolerance factors, formation energies, and elastic constants. Phonon dispersion calculations further demonstrate dynamical stability for Cs2RbCoF6, Cs2RbCoCl6, and Cs2RbCoBr6, whereas Cs2RbCoI6 exhibits imaginary phonon modes, indicating a dynamical instability of the ideal cubic phase. The bulk, shear, and Young’s moduli, Debye temperature, melting temperature, and average acoustic sound velocity exhibit systematic trends across the halide series. Electronic structure calculations reveal semiconducting behavior, with GGA-PBE predicting direct X-point band gaps for Cs2RbCoF6, Cs2RbCoCl6, and Cs2RbCoBr6, whereas Cs2RbCoI6 exhibits an indirect Γ→X gap. HSE06 substantially increases the calculated band gaps and predicts an indirect Γ→X character for all four compounds, highlighting the sensitivity of the band-edge topology to the exchange-correlation treatment. The optical properties, evaluated at the GGA-PBE level, show enhanced low-energy absorption for the Cs2RbCoCl6, Cs2RbCoBr6, and Cs2RbCoI6, while Cs2RbCoF6 is predominantly active in the ultraviolet region. These findings underscore the potential of Cs2RbCoX6 as promising lead-free double-perovskite candidates for diverse optoelectronic and photonic technologies, depending on their specific electronic and optical responses.
This study employed density functional theory (DFT) within Quantum ESPRESSO to
investigate the structural, electronic, phonon, mechanical, optical, and thermodynamic
properties of cubic KSrX₃ (X = F, Cl, Br) halide perovskites for UV optoelectronic applications.
All compounds were found to be structurally, thermodynamically, mechanically, and
dynamically stable, as confirmed by negative formation energies, appropriate Goldschmidt
tolerance factors, Born stability criteria, and phonon spectra without imaginary frequencies.
KSrF₃ exhibited a direct band gap of 5.52 eV, while KSrCl₃ and KSrBr₃ showed indirect band
gaps of 4.45 and 3.75 eV, respectively, making KSrF₃ the most promising candidate for deepUV applications. The compounds exhibited ductile behavior, characterized by dominant ionic
bonding, low Debye temperatures indicative of low lattice thermal conductivity, and
thermodynamic properties consistent with the third law of thermodynamics and Dulong–Petit’s
law. Optical calculations revealed strong UV absorption and static dielectric constants of 2.02,
2.46, and 2.56 for KSrF₃, KSrCl₃, and KSrBr₃, respectively, highlighting their potential for UV
optoelectronic devices.
Rose P. Abang, A. Musa, R. Solomon et al.· Physics Access· 0 citations
A novel X10 benchmark set is introduced to enable an assessment of the computational performance of atomistic simulations of enthalpies of fusion for molecular materials. The fusion enthalpy, i.e. the enthalpy of melting, represents a fundamental descriptor of the solid-liquid equilibrium, and as such, the ability to predict this property is highly valuable across various fields of material design. Computational accuracy is tested for all-atom molecular-dynamics simulations, relying either on a classical generic non-polarizable force-field model (MD), or on a selected density-functional-theory (DFT) treatment of the electronic degrees of freedom in ab initio molecular dynamics (AIMD). Performance of these MD and AIMD methods is critically assessed against reference experimental data and it is evaluated in terms of the fusion enthalpies and related structural descriptors, such as bulk phase densities. A detailed interpretation of the predicted fusion enthalpies in terms of important cohesive non-covalent interactions, such as hydrogen bonding and dispersion forces, and variations of their intensity upon melting is presented. A special emphasis is laid on investigations of the finite-size artifacts that are necessarily at play in costly AIMD simulations that are feasible only for small molecular ensembles. The presented results indicate that the fusion enthalpies for neutral-molecular materials can be typically predicted within roughly 2 kJ mol-1 from the experiment with the PBE-D3(BJ)/GTH based AIMD model, yielding a somewhat higher accuracy on average than the classical force-field based simulations. This finding is important as similar DFT theories are commonly used nowadays as a source of training data for development of machine-learning interatomic potentials.
Jan Ludík, Ctirad Červinka· Physical Chemistry, Chemical...· 0 citations
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