We have investigated intermolecular charge transfer (CT) excited states and demonstrated their contribution to the excitation-relaxation photocarrier generation mechanisms for both ${\mathrm{C}}_{60}$ ${\mathrm{C}}_{70}$ polycrystalline films. This has been done (1) experimentally, using UV-visible absorption (Abs) electroabsorption (EA), luminescence its modulation by external electric-field steady-state photoconductivity; (2) semiempirically, analyzing Abs EA spectra in order determine CT...

Simulations of Density Functional Theory-based ab initio molecular dynamics (AIMD) have been performed for a series aqueous lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) solutions with concentrations ranging from salt-in-water to water-in-salt systems. Analysis the structure electrolytes has revealed preference Li+ cations interact water molecules. In concentrated LiTFSI solutions, molecules form small associates. The total number hydrogen bonds (HBs) in system decreases salt...

Two isomeric anions used in Li-ion conducting electrolytes, TFSI and FPFSI, have been compared through quantum-chemical calculations. The FPFSI anion has more low-energy conformers, its asymmetry leads to an increased number of possible structures FPFSI-Li complexes. preferred geometry the anion-Li ion pair for both is bidentate coordination cation two oxygen atoms; binding effect slightly weaker anion. Ab initio molecular dynamics simulations salt solutions tetraglyme revealed that amount...

Solvent-induced shifts in the absorption spectrum of N,N-diethyl-4-nitroaniline were studied by quantum-chemical methods water, dimethylsulfoxide, acetonitrile and acetone. TDDFT methodology semiempirical ZINDO/S PM6-CIS approaches used to calculate excitation energies. Solvent effect was modeled implicit solvent model different variants PCM approach. Classical molecular dynamics applied obtain solute–solvent geometries explicit modeling. Most models fail reproduce sequence solvatochromic...

Classical molecular dynamics simulations have been performed in polarizable and nonpolarizable force fields for series of electrolytes based on MeTFSI (Me = Li, Na) salts dissolved EMIM–TFSI ionic liquid. Structure the solvation shell Me+ ions investigated. Contributions to total conductivity electrolyte arising from motions different cross-correlations between them analyzed. The analysis has indicated that regardless type cation, liquid anions are positively correlated, contributing toward...

Electronic structures of C60 and its endohedral complexes with Li, Na, K, Be, Mg, Ca, La, B, Al have been calculated by means density functional methodology. The electronic distributions analyzed from the point view guest-host electron transfer. Alkali metals found to donate their outermost fullerene cage. There is no transfer for while La only partial. For entire series, ionization potentials affinities which are in excellent agreement few values known experiments. results consistent...

Classical molecular dynamics simulations were performed for Na+ conducting electrolytes based on EMIM-TFSI ionic liquid and NaTFSI salt. Several parametrizations of force fields have been tested, including polarizable with dipole polarizabilities or Drude-type polarization. Trajectories up to 1 μs long used estimate viscosities, diffusion coefficients, conductivities increasing amount sodium Results compared available experimental data. In most cases the best agreement measured values has...

Analysis of the hydrogen bond network in aprotic ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI) has been performed based on structures obtained from ab initio or classical molecular dynamics simulations. Statistics different donor and acceptor atoms amount chelating bifurcated bonds presented. Most EMIM-TFSI are formed with oxygen as acceptors; most probable those a mixed pair nitrogen acceptors. Spectral graph analysis shown that cations may form up...

Although the electrical conductivity of an electrolyte can be estimated from molecular dynamics trajectory, it is often a challenging task because need to obtain substantial amount data ensure sufficient averaging. Here, we present analysis on convergence results with number simulated trajectories. A series simulations have been performed for model (NaCl in water) and Einstein relation has used calculate conductivity. The standard deviation estimates relatively large compared mean value,...

A polarizable continnum model study and explicit solvation in water investigated through GPU-accelerated ab initio molecular dynamics followed by quantum-chemical calculations have been applied to the process of spiropyran merocyanine isomerization two derivatives. It has found that interaction with only one or molecules is sufficient stabilize respect form. shown agreement between energies obtained implicit solvent models depends on structure system possible specific interactions (hydrogen...

Classical, polarizable molecular dynamics simulations have been performed for a series of Mg(N(SO2CF3)2)2–dimethoxyethane electrolytes with salt concentration varying in the range c = 0.1–1.2 M. It has found that dimethoxyethane solutions, magnesium exists as free ions, metal cations coordinated to solvent molecules. Cation–solvent interactions favor TTT, TGT, and TGG′ conformations dimethoxyethane, modifying population conformers electrolyte. Mg2+ ions form stable solvates about three Two...

Classical and ab initio molecular dynamics (MD) simulations have been performed for electrolytes based on LiTFSI NaTFSI solutions in ethylene carbonate its mono- difluoro derivatives. Differences between with Li+ or Na+ ions the effect of fluorination structure transport properties analyzed. The observed differences are related to strength Me+-carbonate binding, which is weaker cation and/or fluorinated solvents. Infrared spectra computed from MD density functional tight binding (DFTB)...

A three-dimensional analog of the Merrifield model coupling between Frenkel and charge-transfer (CT) excitons C60 fullerene crystal is presented. The based on nearest-neighbor approximation for off-diagonal interactions essentially nonempirical. parameters are estimated from free-molecule data results theoretical calculations published by other authors. band structure CT in calculated discussed context available experimental evidence. Residual ambiguities parametrization removed calculation...

Relative complexation energies for the lithium cation in acetonitrile and diethyl ether have been studied. Quantum-chemical calculations explicitly describing solvation of Li+ performed based on structures obtained from molecular dynamics simulations. The effect an increasing number solvent molecules beyond first shell has found to consist reduction differences different coordination numbers. Explicit-solvation data served as a benchmark results polarizable continuum model (PCM)...

Quantum-chemical calculations and classical molecular dynamics simulations with the Optimized Potentials for Liquid Simulations-All Atom (OPLS-AA) force field are presented ionic liquids based on 2,5,8,11-tetraoxatridecan-13-oate anion (TOTO) alkali cations (Li, Na, K). Complexation energies decrease increasing cation radius from Li to K. Cation interactions carboxylate oxygen atoms preferred over complexation ether oxygens. Cross-linking occurs in structure of liquid because multiple metal...

Classical and ab initio molecular dynamics simulations have been performed for a series of electrolytes Na-ion devices based on sodium bis(fluorosulfonyl)imide (NaFSI) solutions in 1-ethyl-3-methylimidazolium FSI (EMIM-FSI) ionic liquid. Viscosities conductivities estimated polarizable force field agree with experimental data. Fourier transform the autocorrelation function dipole moment obtained has used to calculate IR spectra electrolytes. Computed shifts vibrational band originating from...

We investigated the performance of computationally effective GFN2-xTB approach in molecular dynamics (MD) simulations liquid electrolytes for lithium/sodium batteries. The studied systems were LiTFSI and NaTFSI solutions ethylene carbonate or fluoroethylene neat solvents. focused on structure manifestations ion-solvent interactions vibrational spectra. IR spectra calculated from MD trajectories as Fourier transforms dipole moment. results compared to data obtained ab initio MD. spectral...

We use a transfer-matrix method to study the disorder-induced metal-insulator transition. take isotropic nearest-neighbor hopping and an onsite potential with uniformly distributed disorder. Following previous work done on simple-cubic lattice, we perform numerical calculations for body-centered cubic face-centered lattices, which are more common in nature. obtain localization length from calculated Lyapunov exponents different system sizes. This data is analyzed using finite-size scaling...

Molecular dynamics simulations employing a polarizable force field have been performed for the model poly(ethylene oxide)/LiClO4 electrolytes with boron or aluminum centers. Influence of Lewis acid centers on radial distribution functions, coordination numbers, percentage free cations, diffusion coefficients and conductivity has investigated. Results confirm effect ion complexation show that properties electrolyte result from interplay different interactions.

Molecular dynamics simulations have been applied to study properties of ternary oligoglyme/ionic liquid/lithium salt electrolytes. Different types lithium coordination and phase behavior observed depending on the liquid/salt anion: from full separation Li(+) exclusively anions in systems with BF4(-) rather homogeneous prevailing Li(+)-hexaglyme for FSI(-) or B(CN)4(-) anion. Observed structural successfully correlated binding energies Li(+)-glyme complexes solution calculated within an...

Classical molecular dynamics simulations have been performed for a series of electrolytes based on sodium bis(fluorosulfonyl)imide or bis(trifluoromethylsulfonyl)imide salts and monoglyme, tetraglyme, poly(ethylene oxide) as solvents. Structural properties assessed through the analysis coordination numbers binding patterns. Residence times Na–O interactions used to investigate stability solvation shells. Diffusion coefficients ions electrical conductivity estimated from trajectories....

Superphanes are a group of organic molecules from the cyclophane family. They characterized by presence two parallel benzene rings joined together six bridges. If these bridges sufficiently long, superphane cavity can be large enough to trap small or ions. Using ab initio (time scale 80 ps) and classical (up 200 ns) molecular dynamics (MD) methods, we study behavior five fundamental (M = H2O, NH3, HF, HCN, MeOH) encapsulated inside experimentally reported lantern-like its derivatives...