Structure and intermolecular interactions in ionic liquid 1-ethyl-3-methylimidazolium bromide and its aqueous solutions investigated by vibrational spectroscopy and quantum chemical computations.

The recently developed efficient protocol to explicit quantum mechanical modeling of structure and IR spectra of liquids and solutions (S. A. Katsyuba, S.

Structural flexibility of favipiravir and its structural analogues in solutions: experimental and computational insight.

Combined UV-vis and quantum chemical studies of the structural flexibility and tautomerism of 6-R-3-hydroxy-2-pyrazine carboxamides in solutions revealed that their keto-enol transformations are accompanied by the deprotonation of enol tautomers and the formation of the corresponding anionic species. Both the solvent and the 6-R substituent strongly influence the relative abundance of the above forms in solutions. Anions are not formed in 1,2-dichloroethane (DCE), but the probability of deprotonation in neutral water and ,-dimethylformamide (DMF) increases in the order R = H < F < NO.

Computationally assisted vibrational spectroscopy of nucleic acid bases. 2. Thymine.

As in the case of cytosine [Phys. Chem. Chem.

Computational analysis of the vibrational spectra and structure of aqueous cytosine.

The recently developed efficient protocol for the explicit quantum mechanical modeling of the structure and IR spectra of liquids and solutions [Katsyuba , , 2020, , 6664-6670] is used to describe aqueous solutions of cytosine. The same cluster model of a solute surrounded by the first solvation shell of solvent molecules was shown to be sufficient to reproduce experimental vibrational frequencies and relative IR and Raman intensities. An equally good quality of Raman spectra was provided by B3LYP-D3/def2-TZVP and B3LYP-D3/aug-cc-pVDZ simulations.

Engineering the Exchange Spin Waves in Graded Thin Ferromagnetic Films.

The results of experimental and theoretical studies of standing spin waves in a series of epitaxial films of the ferromagnetic Pd1−xFex alloy (0.02 < x < 0.11) with different distributions of the magnetic properties across the thickness are presented.

Thermodynamics of trans/gauche conformational equilibria and vibrational spectra of 1,2-dihaloethanes in various media.

The recently developed efficient protocols to implicit [Grimme et al., J. Phys.

Ultrafast signatures of magnetic inhomogeneity in Pd Fe ( ≤ 0.08) epitaxial thin films.

A series of Pd Fe alloy epitaxial films ( = 0, 0.038, 0.062, and 0.

Controllable two- and three-state magnetization switching in single-layer epitaxial Pd Fe films and an epitaxial PdFe/Ag/PdFe heterostructure.

We have investigated the low-temperature magnetoresistive properties of a thin epitaxial PdFe film at different directions of the current and the applied magnetic field. The obtained experimental results are well described within an assumption of a single-domain magnetic state of the film. In a wide range of the appled field directions, the magnetization reversal proceeds in two steps via the intermediate easy axis.

What quantum chemical simulations tell us about the infrared spectra, structure and interionic interactions of a bulk ionic liquid.

The recently developed efficient protocol to explicit quantum mechanical modeling of the structure and IR spectra of liquids and solutions [Katsyuba , , 2020, , 6664-6670] is applied to ionic liquid 1-ethyl-3-methyl-imidazolium tetrafluoroborate [Emim][BF], and its C2-deuterated analog [Emim-d][BF]. It is shown that the solvation strongly modifies the frequencies and IR intensities of both cationic and anionic components of the ionic liquids. The main features of the bulk spectra are reproduced by the simulations for cluster ([Emim][BF]), representing an ion pair solvated by the first solvation shell.

Computer-aided simulation of infrared spectra of ethanol conformations in gas, liquid and in CCl solution.

The recently developed efficient protocol combining implicit and explicit, accurate quantum-mechanical modeling of the condensed state (Katsyuba et al., J. Chem.

Revisiting conformations of methyl lactate in water and methanol.

The recently developed efficient protocols to implicit [Grimme et al., J. Phys.

Synthesis, Characterization, and Magnetoresistive Properties of the Epitaxial PdFe/VN/PdFe Superconducting Spin-Valve Heterostructure.

A thin-film superconductor(S)/ferromagnet(F) F1/S/F2-type PdFe(20 nm)/VN(30 nm)/PdFe(12 nm) heteroepitaxial structure was synthesized on (001)-oriented single-crystal MgO substrate utilizing a combination of the reactive magnetron sputtering and the molecular-beam epitaxy techniques in ultrahigh vacuum conditions. The reference VN film, PdFe/VN, and VN/PdFe bilayers were grown in one run with the target sample. In-situ low-energy electron diffraction and ex-situ X-ray diffraction investigations approved that all the PdFe and VN layers in the series grew epitaxial in a cube-on-cube mode.

Antimicrobial drug resistance mechanisms among Mollicutes.

Representatives of the Mollicutes class are the smallest, wall-less bacteria capable of independent reproduction. They are widespread in nature, most are commensals, and some are pathogens of humans, animals and plants. They are also the main contaminants of cell cultures and vaccine preparations.

Fast and Accurate Quantum Chemical Modeling of Infrared Spectra of Condensed-Phase Systems.

An efficient approach for an accurate quantum mechanical (QM) modeling of infrared (IR) spectra of condensed-phase systems is described. An ensemble of energetically low-lying cluster structures of a solute molecule surrounded by an explicit shell of solvent molecules is efficiently generated at the semiempirical tight-binding QM level and then reoptimized at the density functional theory level of theory. The IR spectrum of the solvated molecule is obtained as a thermodynamic average of harmonically computed QM spectra for all significantly populated cluster structures.

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates.

Single-layer vanadium nitride (VN) and bilayer PdFe/VN and VN/PdFe thin-film heterostructures for possible spintronics applications were synthesized on (001)-oriented single-crystalline magnesium oxide (MgO) substrates utilizing a four-chamber ultrahigh vacuum deposition and analysis system. The VN layers were reactively magnetron sputtered from a metallic vanadium target in Ar/N plasma, while the Pd Fe layers were deposited by co-evaporation of metallic Pd and Fe pellets from calibrated effusion cells in a molecular beam epitaxy chamber. The VN stoichiometry and Pd Fe composition were controlled by X-ray photoelectron spectroscopy.

Fast Quantum Chemical Simulations of Infrared Spectra of Organic Compounds with the B97-3c Composite Method.

The ability of the quantum chemical computations to reproduce spectral positions and relative intensities of infrared (IR) bands for experimental vibrational spectra of organic molecules is assessed. The efficient B97-3c density functional approximation, routinely applicable to hundreds of atoms on a single processor, has been applied for the simulation of IR spectra for species containing up to 216 atoms. The results demonstrate that B97-3c, being much faster than the well-recognized hybrid functional B3LYP, offers similarly good quantitative performance in comparison to experimental data for relative IR intensities and fundamental frequencies (ν ≤ 2200 cm) for isolated molecules comprising from 3 to 21 first- or second-row atoms.