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Stacking faults along the (111) direction in low-temperature metastable aluminum oxide (η-Al₂O₃ and χ-Al₂O₃) are studied using density functional theory (DFT). The surface energy of Al₂O₃ (111) is calculated; the intermediate layer between crystalline domains is considered; the ²⁷Al nuclear quadrupole coupling constants are determined.

We review the properties of simple diatomic molecular glasses as explored by nuclear magnetic resonance techniques and measurements of the dielectric susceptibility. We focus on the behavior of classical molecular rotors formed by solid N₂-Ar mixtures and discuss the time dependent behavior in terms of replica symmetry breaking theories.

We report solid-state ³⁵Cl NMR spectra in three hexachlorides, (NH₄)₂SeCl₆, (NH₄)₂TeCl₆ and Rb₂TeCl₆. The C_Q (³⁵Cl) quadrupole coupling constants in the three compounds were found to be 41.4±0.1 MHz, 30.3±0.1 MHz and 30.3±0.1 MHz, respectively, some of the largest C_Q (³⁵Cl) quadrupole coupling constants ever measured in polycrystalline powdered solids directly via ³⁵Cl NMR spectroscopy. The ³⁵Cl EFG tensors are axial in all three cases reflecting the C _{4 v} point group symmetry of the chlorine sites. ³⁵Cl NMR experiments in these compounds were only made possible by employing the WURST-QCPMG pulse sequence in the ultrahigh magnetic field of 21.1 T. ³⁵Cl NMR results agree with the earlier reported ³⁵Cl NQR values and with the complementary plane-wave DFT calculations. The origin of the very large C_Q (³⁵Cl) quadrupole coupling constants in these and other main-group chlorides lies in the covalent-type chlorine bonding. The ionic bonding in the ionic chlorides results in significantly reduced C_Q (³⁵Cl) values as illustrated with triphenyltellurium chloride Ph₃TeCl. The high sensitivity of ³⁵Cl NMR to the chlorine coordination environment is demonstrated using tetrachlorohydroxotellurate hydrate K[TeCl₄(OH)]×0.5H₂O as an example. ¹²⁵Te MAS NMR experiments were performed for tellurium compounds to support ³⁵Cl NMR findings.

The mobility of water molecules in natural natrolite (Na₂Al₂Si₃O₁₀×2H₂O) is investigated by the ¹H NMR method. The spin-lattice relaxation times in the laboratory and rotating frames ( T ₁ and T _1r) are measured as a function of the temperature for a polycrystalline sample. From experimental T ₁ data it follows that at T > 286 K the diffusion of water molecules along channels parallel to the c axis is observed. From experimental T _1r data it follows that at T > 250 K the diffusion of water molecules in transversal channels of natrolite is also observed. At a low temperature ( T < 250 K) the dipolar interaction with paramagnetic impurities (presumably Fe³⁺ ions) becomes significant as a relaxation mechanism of ¹H nuclei.

The ionic mobility and conductivity in the crystalline phases of PbSnF₄- x CaF₂ systems ( x = 2.5 mol.%, 5 mol.%, 7.5 mol.%, and 10 mol.%) in the temperature range of 150-500 K are studied by NMR and impedance spectroscopy. The parameters of ¹⁹F NMR spectra, types of ion motions, and ionic conductivity in the PbSnF₄ compound doped with calcium fluoride are found to be determined by the temperature and concentration of calcium fluoride. The specific conductivity of the crystalline phases in the PbSnF₄-CaF₂ systems is rather high at room temperature, and hence, one cannot exclude the possibility to use them for the creation of functional materials with a high ionic (superionic) conductivity.

A comparative structural study of LiMPO₄ (M = Mn, Fe, Co, Ni) orthophosphates and Li₂MPO₄F (M = Co, Ni) fluorophosphates obtained by mechanochemically assisted solid-state synthesis is performed using powder XRD, IR, and NMR spectroscopy methods. It is shown that all compounds crystallize in the orthorhombic symmetry (space group Pnma ). Lattice parameters decrease on passing from Mn to Ni, which is due to the decrease in the ionic radius of the d metal. According to the IR spectroscopy data, in this series an increase in the covalency of the P-O bond is observed along with a decrease in the covalency of the M-O bond. On passing to fluorophosphates, the symmetry of PO₄ tetrahedra increases. ⁶Li and ³¹P NMR spectra of all compounds are characterized by the dependence of the contact shift on the nature of metal M and the degree of distortion of the MO₆ coordination polyhedron. ⁶Li MAS NMR line width is noticeably affected by the concentration of structural defects. Unlike orthophosphates with equivalent lithium ions, fluorophosphates contain lithium ions in three different positions.

Distributions described by the Bloembergen-Rowland (BR) formula and widely used in NMR of solids for studying polycrystalline samples, which is closely connected with the problem of constructing the convolutions of such distributions with a broadening symmetric function, are strictly area normalized. The application of the obtained methodological results is illustrated by the example of the analysis of NMR data for UF₆.

The temperature and concentration dependences of ²⁰⁷Pb NMR chemical shifts of Pb(NO₃)₂ in D₂O are reported. The results are analyzed in terms of exchange between a solvated lead ion and the Pb(NO₃)⁺ contact-ion pair. Predictions of the chemical shift difference between the aquated ion and contact-ion pair are carried out for the gas-phase entities and for the solvated species with a DFT calculation. Previously reported data on ²⁰⁷Pb NMR chemical shifts of Pb(NO₃)₂ in H₂O are reevaluated. From the analysis, the enthalpy of dissociation of the contact-ion pair is found to be -42.3±1.0 kJ/mol.

Quantum chemical calculations of the [Mo₃S₇(Et₂dtc)₃](Et₂dtc) complex in different solvents are performed. It is shown that the binding energy between the cluster [Mo₃S₇(Et₂dtc)₃]⁺ cation and the outer-sphere (Et₂dtc)^- anion exponentially decreases with increase in the solvent dielectric permittivity. By DOSY NMR it is determined that in chloroform, the cationic and anionic moieties of the complex form an associate (contact ion pair), while in strongly polar dimethyl sulfoxide these moieties move independently of one another.

Optical and magneto-optical properties of solutions of crude oil of different origin (i.e., taken from different fields) are studied in the visible and near-UV region of optical emission. Magnetic circular dichroism (MCD) spectra of oil are obtained in the vicinity of wavelengths of ~410 nm, 533 nm, and 576 nm. It is demonstrated that the intensity of the MCD signal depends on the origin of crude oil, and it is proportional to the oil concentration in the solution. The comparison of the magneto-optical spectroscopy data with the chemical composition of samples allows us to conclude that the observed magneto-optical activity is determined by the presence of VO²⁺ complexes in the oil samples studied. The revealed magneto-optical activity of conventional oil can form a basis of a new method for the analysis of the composition and properties of oil of different origin.