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The ternary Tb2–x Nd x Zn17–y Ni y (x = 0.5, y = 4.83) disordered phase belongs to the structural family based on the rhombohedral Th2Zn17 structure type. The structure is maximally disordered since all the sites are occupied by statistical mixtures of atoms. The Tb/Nd mixture of atoms occupies the 6c site (site symmetry 3m). The statistical mixtures Ni/Zn consisting of more Ni atoms are located in the 6c and 9d (symmetry .2/m) sites. In the following 18f (site symmetry .2) and 18h (site symmetry .m) sites are located Zn/Ni statistical mixtures which consist of more Zn atoms. Zn/Ni atoms form three-dimensional networks with hexagonal channels that fill statistical mixtures of Tb/Nd and Ni/Zn. The Tb2–x Nd x Zn17–y Ni y compound belongs to the family of intermetallic phases capable of absorbing hydrogen. In the structure, there are three types of voids, namely, 9e (site symmetry .2/m), 3b (site symmetry \overline{3}m) and 36i (site symmetry 1), in which hydrogen can be inserted, and the maximum total absorption capacity can reach 1.21 wt% H2. Electrochemical hydrogenation shows that the phase absorbs 1.03% of H2, which indicates partial filling of the voids with H atoms.

Three new iridium aluminum intermetallics CaAl4Ir2, SrAl4Ir2, and EuAl4Ir2 were synthesized from the elements using silica or tantalum ampoules. They crystallize in the tetragonal crystal system with space group P4/ncc and lattice parameters of a = 782.20(1) and c = 779.14(2) pm for CaAl4Ir2, a = 797.62(1) and c = 772.75(2) pm for SrAl4Ir2, and finally a = 791.78(5) and c = 773.31(5) pm for EuAl4Ir2. All compounds crystallize isostructurally and adopt a new structure type that can be derived from the KAu4In2 type structure. To compare the structures from a crystallographic point of view, a group–subgroup relation between KAu4In2 and EuAl4Ir2 as well as KAu4In2 and KAu4Sn2 have been established using the Bärnighausen formalism. Finally, quantum-chemical calculations have been conducted, showing that in all three title compounds, a polyanionic [Al4Ir2]δ– network exists with significant (polar) bonding interactions, while the respective Caδ+, Srδ+, and Euδ+ cations are located in octagonal channels. Graphical abstract

YNiIn and YCuIn form complete solid solutions YNiIn1−x Al x and YCuIn1−x Al x , which were characterized on the basis of X-ray powder diffraction. The ZrNiAl type crystal structures (space groups P 6 ‾ 2 m $P\overline{6}2m$ ) of YNiAl (a = 0.70386(9), c = 0.38327(4) nm, wR 2 = 0.0424), YNiIn0.77Al0.23 (a = 0.73895(9), c = 0.37707(4) nm, wR 2 = 0.0498) and YCuIn0.63Al0.37 (a = 0.73404(7), c = 0.39045(4) nm, wR 2 = 0.0314) were refined from the single crystal X-ray diffraction data. Exemplarily the electronic structure of YNiAl was studied, manifesting substantial Ni–Al bonding within the three-dimensional [NiAl] substructure. Comparison of YNiAl with isotypic YNiIn shows stronger Ni–Al bonding as compared to Ni–In. Magnetic susceptibility measurements of YNiIn1−x Al x (x = 0.1, 0.2, 0.7 and 0.9), YNiIn and YNiAl in the temperature range 3–300 K indicated Pauli paramagnetic behaviour with molar magnetic susceptibility of about 0.15–0.22 × 10−3 emu/mol.

The Laves phase Mg2MnGa3 was synthesized from the elements by arc-melting and subsequent annealing in a silica ampoule at T = 670 K. The structure of Mg2MnGa3 was refined from single-crystal X-ray diffractometer data: URe2 type, Cmcm, a = 543.24(1), b = 869.59(3), c = 858.58(2) pm, wR2 = 0.0556, 273 F 2 values and 24 variables. The manganese and gallium atoms form a three-dimensional network of corner- and face-sharing MnGa3 tetrahedra that derive as a ternary ordering variant from the hexagonal Laves phase MgZn2. The structures of the distortion and coloring variants, i.e., MgZn2, URe2, Mg2Cu3Si and Mg2MnGa3 are discussed on the basis of a Bärnighausen tree. The electronic structure calculation data indicate that in addition to the metallic type of bonding an additional covalent interaction appears between the Ga–Ga and Mn–Ga atoms.

The new ternary gallide MgMn4Ga18 (magnesium tetramanganese octadecagallium) was synthesized and its crystal structure determined by means of single-crystal X-ray diffraction. The MgMn4Ga18 structure can be described as that of a three core–shell cluster compound. The Mg atoms are surrounded by 16 adjacent Ga atoms, [MgGa16], and the respective coordination polyhedron is an octadecahedron. This [MgGa16] octadecahedron is encapsulated inside a [Ga32] icohexahedron, which is in turn encapsulated inside a [Ga40] pentacontaoctahedron. As a result, a three core–shell cluster, [MgGa16@Ga32@Ga40], is identified. Electronic structure calculations were performed by means of the TB-LMTO-ASA program and additionally confirm the existence of the core–shell packing of the clusters.

La3.65Mg30Sb1.07, hexagonal, P63/mmc (no. 194), a = 10.3895(2) Å, c = 10.2547(3) Å, V = 958.61(5) Å3, Z = 1, R gt (F) = 0.0166, wR ref(F 2) = 0.0429, T = 293(2) K.

The crystal structures of Eu5Si3 and EuSi were studied in detail by X-ray single-crystal diffraction. The single crystals were selected from arc-melted and annealed samples. X-ray diffraction was performed at room temperature on an Oxford Diffraction X’calibur Atlas four-circle diffractometer (MoKα radiation). Eu5Si3 adopts the tetragonal Cr5B3-type: space group I4/mcm (# 140), Pearson code tI32, Z = 4, a = 7.9339(6), c = 15.308(2) Å. The compounds with equiatomic composition EuSi crystallize in the structure type TlI: space group Cmcm (# 63), Pearson code oS8, Z = 4, a = 4.6955(6), b = 11.1528(13), c = 3.9845(4) Å. The silicides Eu5Si3 and Li2Si form during electrochemical lithiation (charge process) of EuSi. The electrochemical process 5EuSi + 4Li+ + 4e − ↔ Eu5Si3 + 2Li2Si is reversible, and the discharge specific capacity at 1C rate reached 140 mAhg−1 and the Coulombic efficiency is 93%.

The title compound was obtained via a two-step synthesis (Dimroth reaction and amidation) for anti­cancer activity screening and was selected from a 1H-1,2,3-triazole-4-carboxamide library. The cyclo­propyl ring is oriented almost perpendicular to the benzene ring [dihedral angle = 87.9 (1)°], while the dihedral angle between the mean plane of the cyclo­propyl ring and that of the triazole ring is 55.6 (1)°. In the crystal, the mol­ecules are linked by O—H⋯O and C—H⋯N inter­actions into infinite ribbons propagating in the [001] direction, which are inter­connected by weak C—H⋯O inter­actions into layers., The title compound, C15H18N4O2, was obtained via a two-step synthesis (Dimroth reaction and amidation) for anti­cancer activity screening and was selected from a 1H-1,2,3-triazole-4-carboxamide library. The cyclo­propyl ring is oriented almost perpendicular to the benzene ring [dihedral angle = 87.9 (1)°], while the dihedral angle between the mean plane of the cyclo­propyl ring and that of the triazole ring is 55.6 (1)°. In the crystal, the mol­ecules are linked by O—H⋯O and C—H⋯N inter­actions into infinite ribbons propagating in the [001] direction, which are inter­connected by weak C—H⋯O inter­actions into layers. The inter­molecular inter­actions were characterized via Hirshfeld surface analysis, which indicated that the largest fingerprint contact percentages are H⋯H (55.5%), N⋯H/H⋯N (15.4%), C⋯H/H⋯C (13.2%) and O⋯H/H⋯O (12.9%).

Alloys from the region of existence of the solid solution TbCo4.5SixLi0.5-x were synthesized by arc melting. Quantitative and qualitative composition of alloys and powders of electrode materials was determined by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The Tb/Co/Si ratio in the samples was confirmed by X-ray fluorescence spectroscopy. The change in cell parameters within the solid solution existence was established by the results of X-ray powder diffraction (TbCo4.5SixLi0.5-x, x = 0.1–0.4: a = 4.9518(5) – 4.9324(3), c = 3.9727(4) – 3.9746(3) Å). The crystal structure of the solid solution was determined by the Rietveld method (CaCu5 structure type, space group P6/mmm). Cobalt atoms are partially replaced by silicon and lithium only in 2c position. The ability of alloys to reversibly absorb hydrogen was studied by the method of electrochemical hydrogenation. Under experimental conditions the amount of deintercalated hydrogen was about 0.19 H/f.u. The change in cell parameters after hydrogenation (volume increases from 83.74(1) to 85.54(6) Å3) and the stability of the electrode in the electrolyte solution was further confirmed by X-ray phase analysis. Measurements of the electrical resistivity of the samples indicated a decrease of resistivity value with a slight increase in the amount of alkali metal in samples.

The crystal structure of La2Mg17-xSnx solid solution was determined by single crystal X-ray diffraction for the first time. This phase crystallizes in hexagonal symmetry with space group P63/mmc (a = 10.3911(3), c = 10.2702(3) Å, V = 960.36(6) Å3, R1 = 0.0180, wR2 = 0.0443 for the composition La3.65Mg30Sn1.10) and is related to the structure of CeMg10.3 and Th2Ni17-types which are derivative from the CaCu5-type. A series of isotypical solid solutions La2Mg17-xMx (M = Ni, Sn, Sb, x ~0.8) was synthesized and studied by X-ray powder diffraction, energy dispersive X-ray spectroscopy and fluorescent X-ray spectroscopy. All solid solutions crystallize with the structure related to the Th2Ni17-type. The electrochemical hydrogenation confirmed the similar electrochemical behavior of all studied alloys. The amount of deintercalated hydrogen depends on the physical and chemical characteristics of doping elements and increases in the sequence Sn < Mg < Sb < Ni. The most geometrically advantageous sites are octahedral voids 6h of the initial structure, thus a coordination polyhedron for H-atom is an octahedron [HLa2(Mg,M)4].

Two kinds of LixZnO-CNT and La2O3-CNT composite additives (CA) are employed to improve the hydrogen absorption/desorption processes of Li12+xMg3-xSi4-ySny phase. The effect of the addition of composite additives on the improvement of hydrogen sorption kinetics of intermetallic phase is due to the following factors: CA are more stable than Li contain intermetallic; CA provides diffusion pathways to most of the grains inside the material, where the dissociation of H2 molecules into H atoms takes place; CA surface has a relatively higher reactivity to H2 dissociation. The substituted (Si atoms by Sn) and doped by La2O3-CNT composite Li12+xMg3-xSi4-ySny alloy have the highest uptake and release capability (9.8 wt%). LixZnO-CNT give 9.3 wt% hydrogen uptake and release, which are still much better than undoped Li12+xMg3-xSi4-ySny (8.9 wt%). Li12+xMg3-xSi4-ySny is a maximally disordered intermetallic phase (MD-IP) with a cubic structure (I-43d, a = 10.7409(8) A) related to Cu15Si4-type.

Single crystals of a new samarium platinum indide have been synthesized in a high-frequency furnace under flowing argon atmosphere. The crystal structure of SmPt2In2 was determined from single-crystal X-ray data (R1 = 0.0416 for 1049 F values and 63 variables). It belongs to the CePt2In2 structure type with the following crystallographic parameters: P21/m, mP20, Z = 4, a = 10.0561(8), b = 4.4214(2), c = 10.1946(8) Å, β = 116.492(5)°, V = 405.68(5) Å3. Physical properties were studied and the crystal chemical discussion is supported by electronic structure calculations.

The multicomponent alumosilicide Li12Mg3Si3Al (cubic, space group I-43d, cI76) belongs to the structural family based on the Cu15Si4 type. The Li atoms are ordered and occupy the site with symmetry 1 and the Mg atoms occupy the site with -4.. symmetry. The Si/Al statistical mixture occupies the site with .3. symmetry. The coordination polyhedra around the Li atoms are 13-vertex distorted pseudo-Frank–Kasper polyhedra. The environments of the Mg and Si/Al atoms are icosahedral. The hydrogen storage characteristics of Li12Mg3Si3Al were investigated. The reversible hydrogen storage capacity of the title compound is excellent and the gravimetric storage capacity of this new material, corresponding to 9.1 wt% H2, is higher compared to Li12Mg3Si4 (8.8 wt%). The enthalpy of hydrogen desorption is 86 kJ mol−1 and is lower compared to known lithium-based hydrides.

The title compounds have been synthesized by reaction of the elements in sealed tantalum crucibles in a muffle furnace using special annealing sequences. The crystal structures of YbNi2.31Al2.69 (R1 = 0.0100 for 212 F 2 values and 18 variables) and for ErNi2.23Al2.77 (R1 = 0.0154 for 255 F 2 values and 18 variables) were refined from single crystal X-ray data. They belong to the YNi2Al3 type (i3 superstructure of CaCu5) with the following crystallographic parameters: space group P 6 / m m m $P6/mmm$ , Pearson symbol hP18, Z = 3, a = 8.2723(12), c = 4.0672(8) Å, V = 241.03(8) Å3 for YbNi2.31Al2.69 and a = 8.9109(13), c = 4.0669(8) Å, V = 279.66(8) Å3 for ErNi2.23Al2.77. The crystal chemical discussion is supported by electronic structure calculations.

Electrochemical hydrogenation, lithiation and sodiation of the phases GdFe2–xMx and GdMn2–xMx (M=Mn, Co, Ni, Zn, and Mg) and the influence of doping components on electrochemical characteristics of electrode materials on their basis were studied using X-ray powder diffraction method, scanning electron microscopy, energy dispersive X-ray analysis, X-ray fluorescent spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Phase analysis showed a simple correspondence between unit cell parameters of the phases and atomic radii of doping elements. Electrode materials based on GdFe2 and GdMn2 doped with 2 at.% of Co, Ni and Mg demonstrated better hydrogen sorption properties than those doped with Mn and Zn. Corrosion resistance of the doped electrodes was also better than of the binary analogues (e.g. corrosion potential of the GdFe2-based electrode was –0.162 V whereas that of GdFe1.96Ni0.04 was –0.695 V). The capacity parameters were increased in the following ranges: Zn

The new ternary gallide MgMn

Synthesis, structural characterization and chemical bonding peculiarities of two new quaternary selenides of the Tl4Sb8Sn5Se24 and Tl5Sb2Sn4Se14−x (x = 0.5) are reported. The crystal structures of these compounds were determined by single crystal X-ray diffraction analysis. The Tl4Sb8Sn5Se24 phase is a new structure type and crystallizes in the triclinic P 1̅ space group (a = 7.9061(13) Å, b = 13.9035(16) Å, c = 21.4665(17) Å, α = 80.058(8)°, β = 84.727(10)°, γ = 73.542(12)°, wR 2 = 0.0258, 8200 F 2 values, 373 variables). The Tl5Sb2Sn4Se14−x (x = 0.5) phase represents a new structure type with a tetragonal unit cell (P 4/mbm, a = 8.1570(10) Å, c = 21.946(3) Å, wR 2 = 0.0346, 1953 F 2 values, 44 variables). Crystallographic analysis together with linear muffin-tin orbital band structure calculations reveals that both structures we conform to the concept of Zintl-Klemm and exhibit semiconductor properties.

Modifying the surface of nanomaterials, such as carbon nanotubes, by introducing heteroatoms or larger functional groups into the structure causes a change in chemical properties—manifested in the increase in reactivity as well as a change in conductivity. This paper presents the new selenium derivatives obtained by a covalent functionalization of brominated multi-walled carbon nanotubes (MWCNTs). The synthesis was carried out in mild conditions (3 days at room temperature), and was additionally assisted with ultrasound. After a two-stage purification, the obtained products were identified and characterized by the following methods: scanning and transmission electron microscopy imaging (SEM and TEM), energy dispersive X-ray microanalysis (EDX), X-ray photoelectron spectroscopy (XPS), Raman and nuclear magnetic resonance (NMR), and X-ray diffraction (XRD). In the selenium derivatives of carbon nanotubes, the content of selenium and phosphorus reached 14 and 4.2 wt%, respectively.

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.

The crystal structure of the high-temperature modification of the compound Li2Zn5 was determined using single-crystal X-ray diffraction data. It is the first representative of a new binary structure type with triclinic space group P1, where the parameters of the unit cell are a = 8.0073(3)A, b = 11.5956(6)A, c = 15.2956(5)A, α = 96.39°, β = 101.92°, and γ = 108.13°, the formula sum is Li11.748Zn31.113, Z = 2, and CCDC deposit number is 1861780. The title compound has a pseudohexagonal motif, made of 7- and 17-atom Li-zigzag chains and continuous Zn-chains, with the the relative placement of these large aggregates violating hexagonal symmetry. The structure may be decomposed into fragments, related to the AlB2 structure type, and could be obtained from multiplication of the unit cell, multiple substitution of Li atoms by triangles of Zn, insertion of Zn atoms, and deformation. Most structures of Li-Zn compounds, except LiZn, are highly symmetric but disordered. The possible causes of lower symmetry of β-Li2Zn5 were analyzed using the results of DFT calculations. β-Li2Zn5 shows high polarity of bonds, and Li atoms donate part of the electron density to Zn atoms.

The structural and magnetic properties of the RAl0.2Ge2 (R = Tb-Tm) germanides were studied by X-ray and neutron diffraction, scanning electron microscopy and magnetometric techniques. The compounds crystallize in the CeNiSi2-type crystal structure (space group Cmcm). Magnetic measurements reveal an antiferromagnetic ordering below TN equal to 38 K (R = Tb), 23 K (Dy), 9 K (Ho) and 6.5 K (Er), and no magnetic ordering in the Tm-compound down to 1.9 K. Based on the neutron diffraction data the magnetic structures can be described by the propagation vector k = (0.4714(2), 0, 0.3128(2)) for TbAl0.2Ge2 and k = (0.4858(5), 0, 0.3214(6)) for DyAl0.2Ge2 while in HoAl0.2Ge2 and ErAl0.2Ge2 a simple collinear antiferromagnetic ordering of the G-type was observed. The electronic structures of the title compounds were calculated using the tight-binding linear muffin-tin orbital (TB-LMTO) method.

The new ternary compound La3Ni4Al2 has been synthesized and the crystal structure has been studied by X-ray single crystal diffraction. La3Ni4Al2 is the first aluminide, crystallizing in the La3Ni4Ga2-type. The crystal structure of La3Ni4Al2 consists of La-layers and hetero-atomic Ni/Al layers, sequentially alternating along the a axis (pseudo-hexagonal c axis). According to electronic structure calculations using the tight-binding linear muffin-tin orbital method in the atomic-sphere approximation (TB-LMTO-ASA), strong Al–Ni interactions have been established. The coordination polyhedra for the Al atoms are cuboctahedra, whereas the bicapped square prism and bicapped square antiprism are typical for nickel atoms. The lanthanum atoms are enclosed in pseudo Frank–Kasper polyhedra.

The new quaternary aluminide Li20Mg6Cu13Al42 was synthesized from the elements in a sealed tantalum crucible. The crystal structure was studied by single crystal and confirmed by X-ray powder diffraction. Li20Mg6Cu13Al42 {cI162, Im{\overline 3}, a = 13.8451 (2), R[F 2 > 2σ(F 2)] = 0.023} crystallizes as an ordered version of Mg32(Al,Zn)49 and Li—Cu—X (X = Al, Ga, Si) periodic crystals containing icosahedral clusters. The Li20Mg6Cu13Al42 structure can also be described as three-shell icosahedral clusters of [CuAl12@Li20Cu12@Al60], enclosed inside a distorted triacontahedron. The electronic structure calculations were performed by means of the TB-LMTO-ASA program and confirm the core–shell packing of these clusters. The isostructural compound of Li20Mg6Cu13Ga42 was found in a Li–Mg–Cu–Ga quaternary system.

Mg-rich region of phase diagram of the Mg-Li-Al ternary system was investigated by means XRD, SEM/WDS and EPMA methods. The Mg-based solid solution extend up to Mg76Li12Al12 composition. The Mg76Li12Al12Hx hydrides were prepared by different methods, such as gas phase hydrogenation and thermal synthesis. Two hydride phases forms at the interaction of Mg76Li12Al12 alloy with hydrogen. In the first stage, the insertion of hydrogen in to the structure of the initial hexagonal phase up to the maximum content of hydrogen equal 3.2 wt.% was observed. This Mg76Li12Al12Hx (0

New ternary phase Tb2Ni5C3 was gained in the three-phases sample of nominal composition after 90 d annealing at 800 °C. Crystal structure of Tb2Ni5C3 was determined using synchrotron powder diffraction: structure type La2Ni5C3, space group P4/mbm, a = 8.2372(1) A, c = 3.83402(6) A, RB = 5.0%; Rp = 1.8%. Crystallographic analysis and electronic structure calculations confirm the La2Ni5C3-isotypes including Tb2Ni5C3 refer to carbometalates. Metallic bonding is predominant in the R2Ni5C3 compounds. Novel La2Ni5C3-isotypic compounds were synthesized with rare earths Sm and Gd. Their unit cell parameters have been determined from X-ray powder diffraction data.

The multicomponent alumosilicide Li

The crystal structure of MgCoGa

The crystal structure of new Mg9Ni6Ga14and Mg3Ni2Ga compounds were investigated by single-crystal diffraction. Both structures can be described as three-core-shell cluster compounds. In the Mg6Ni9Ga14structure, the [Ni6Ga6] icosahedron is encapsulated within the [Mg20] dodecahedron, which is again encapsulated within a [Ni18Ga42] fullerene-like truncated icosahedron, thus the three core–shell cluster [Ni6Ga6@Mg20@Ni18Ga42] results. In the Mg3Ni2Ga structure, the [Mg6] octahedron is encapsulated within the [Ni12Ga6] flattened icosahedron in vertices of which there are 12 nickel atoms, and six lateral edges are centered by gallium atoms, which in turn is encapsulated within a [Mg36] pseudo-rhombicuboctahedron with 12 additional atoms centering the lateral faces; thus for Mg3Ni2Ga the three-shell cluster is [Mg6@Ni12Ga6@Mg36].

The crystal structure of MgCoGa2 (magnesium cobalt digallide) was solved by direct methods and refined in two space groups as P21/c (standard choice) and P21/n (non-standard choice). The refined lattice parameters for the standard choice are a = 5.1505 (2), b = 7.2571 (2), c = 8.0264 (3) Å and β = 125.571 (3)°, and for the non-standard choice are a = 5.1505 (2), b = 7.2571 (2), c = 6.5464 (2) Å and β = 94.217 (3)°. All parameters for MgCoGa2 refined to R 1 = 0.027 and wR 2 = 0.042 using 594 reflections. The crystal structure peculiarities of this compound are discussed. Particular attention has been given to relationships with other similar structures, such as YPd2Si and Fe3C. Crystallographic analysis, together with linear muffin-tin orbital electronic structure calculations, reveals the presence of three-dimensional polyatomic nets with partial covalent bonding between the Ga atoms.