We present the crystallographic program Jana2020, the successor of Jana2006. Jana2020 has new, technically different graphics and structure plot-driven intuitive control. Tools known from Jana2006 were revised and inserted into a new logical scheme, and their control connected with the structure plot. Some of the tools were considerably improved. We focus on the details of the most dynamically developing parts, namely twinned structures, magnetic structures, and structure analysis based on electron diffraction data.

The system SrO(SrTiO3) n contains promising compounds for several applications, whose functionalities all depend in particular on the band structure of the respective crystal. While the electronic structure of SrO and SrTiO3 is sufficiently clarified in literature, there is a lack of information concerning the Ruddlesden–Popper (RP) phases. In this work, density functional theory is used to compute the electronic structure for the homologous series with n = 0–3, ∞. The according band structures are presented and effective masses are given for the complete system. In addition, the calculations are consulted to discuss the thermodynamical stability of the RP phases, confirming the gain of formation energy up to n = 3, as reported in recent literature. A promising possibility for applications has been found, analyzing theses band structures: As the optical gaps at distinct high-symmetry points of the Brillouin zone show different dependencies on the lattice parameters, as it is reported for SrO in literature, a similar behavior could be expected in particular for the RP phase with n = 1.

Dolomite-type MSn(BO3)2 phases for M = Mn, Fe, Co and Ni have been synthesized using solid-state synthesis carried out in sealed quartz tubes. X-ray powder diffractiondata Rietveld refinements confirm the rhombohedral space group R 3 ‾ $R\overline{3}$ for all compositions. The change in unit-cell parameters follows the increasing nature of the radius of the M-cations. Both the MO6 and SnO6 octahedra are found to be quite regular. 119Sn Mössbauer spectroscopy investigations complement the almost undistorted nature of the SnO6 octahedra and the tetra-valent charge of the tin-atoms. Detailed vibrational features are described from the Raman and the FTIR spectral data collected at ambient conditions. The frequency shifts of some selective Raman and IR bands are explained in terms of the change of cationic sizes and the respective M–O bond distances. The UV/Vis diffuse reflectance data are analyzed using the RATD method, leading to direct bandgaps for all the investigated samples. The wide bandgap semiconductors (3 – 4 eV) show increasing transition energies with increasing cation sizes of the high-spin M-cations in the dolomite types.

A new copper(II) complex [Cu(3,5,6-tcpa)(2,2′-bipy)Cl] (1) has been obtained through the one-pot hydrothermal reaction of copper chloride dihydrate with triclopyr (systematic name 2-((3,5,6-trichloropyridin-2-yl)oxy)acetic acid, abbreviation 3,5,6-Htcpa) and 2,2′-bipyridine (2,2′-bipy) coligands. 1 has crystallized in triclinic crystal system, P 1 ‾ $\overline{1}$ space group. The central copper(II) ion displayed a distorted square–pyramidal geometry and was connected by one chlorido co-ligand (Clˉ), one 3,5,6-tcpa anionic chelator and one chelating 2,2’-bipy ligand to afford a mononuclear structure. 1 is further extended into a 3D network by the non-covalent interactions of H⋯Cl, H⋯O hydrogen bonds, aromatic π⋯π stacking together with Cl⋯Cl halogen bond interactions. The co-crystallization process, the crystal structure of 1 as well as the Hirshfeld surface analysis for 1 have been analyzed and described. In addition, the flexible conformation of phenoxy methylene group among 1, triclopyr acid and its previously reported co-crystallized compound also have been carefully compared and discussed.

The metal-rich phosphide TaCrP forms from the elements by step-wise solid state reaction in an alumina crucible (maximum annealing temperature 1180 K). TaCrP is trimorphic. The structural data of the hexagonal ZrNiAl high-temperature phase (space group P 6 ‾ 2 m $P\overline{6}2m$ ) was deduced from a Rietveld refinement. At room temperature TaCrP crystallizes with the TiNiSi type (Pnma, a = 623.86(5), b = 349.12(3), c = 736.78(6) pm, wR = 0.0419, 401 F 2 values, 20 variables) and shows a Peierls type transition below ca. 280 K to the monoclinic low-temperature modification (P121/c1, a = 630.09(3), b = 740.3(4), c = 928.94(4) pm, β = 132.589(5)°, wR = 0.0580, 1378 F 2 values, 57 variables). The latter phase transition is driven by pairwise Cr–Cr bond formation out of an equidistant chain in o-TaCrP. The phase transition was monitored via different analytical tools: differential scanning calorimetry, powder synchrotron X-ray diffraction, magnetic susceptibility measurements and 31P solid state NMR spectroscopy.

An achiral tripeptide, namely, Boc-γ-Abu-m-ABA-Aib-OMe (γ-Abu: γ−amino butyric acid; m-ABA: meta-aminobenzoic acid) was synthesized by solution phase procedure. The α, γ-hybrid peptide was designed in such a way that two dissimilar γ−amino acids, one flexible and another rigid, were positioned sidewise along with α-amino isobutyric acid (Aib) as C-terminal residue. The single crystal X-ray diffraction analysis revealed that two kinks were generated around centrally placed m-ABA. Interestingly, the peptide self-assembled via three intermolecular N–H···O and one intermolecular C–H···O hydrogen bonding interactions to supramlecular helical architecture.

The magnesium-rich intermetallic compounds Gd5Cu5Mg13 and Tb5Cu5Mg13 were obtained from direct reactions of the elements (induction melting) in sealed tantalum ampoules. Both compounds crystallize with the orthorhombic Y5Cu5Mg13 type structure, space group Cmcm and Z = 4. The polycrystalline samples were characterized by powder X-ray diffraction. The structure of the gadolinium compound was refined from single crystal X-ray diffraction data: a = 414.78(2), b = 1921.87(12), c = 2573.89(16) pm, wR2 = 0.0492, 1611 F 2 values and 77 variables. Refinement of the occupancy parameters revealed a small degree of Gd/Mg mixing for the Gd3 site, leading to the composition Gd4.93(1)Cu5Mg13.07(1) for the studied crystal. The Gd5Cu5Mg13 structure contains slabs of equiatomic GdCuMg, which are embedded in a magnesium matrix. From a geometrical point of view, one can describe the Gd5Cu5Mg13 and Tb5Cu5Mg13 structures as intergrowth variants of distorted W/CsCl and AlB2 related slabs. The most remarkable crystal chemical feature concerns the bcc like magnesium slabs with short Mg–Mg distances ranging from 300 to 342 pm. Temperature dependent magnetic susceptibility measurements show Curie-Weiss paramagnetism for Tb5Cu5Mg13 (10.5(1) μ B Tb atom−1 and Θ P = −11.6(1) K). Antiferromagnetic ordering was detected below the Néel temperatures of T N = 30.5(3) K.

This mini-review focuses on up-to-date advances of hybrid materials consisting of organic and inorganic components and their applications in different chemical processes. The purpose of forming such hybrids is mainly to functionalize and stabilize inorganic supports by attaching an organic linker to enhance their performance towards a target application. The interface chemistry is present with the emphasis on the sustainability of their components, chemical changes in substrates during synthesis, improvements of their physical and chemical properties, and, finally, their implementation. The latter is the main sectioning feature of this review, while we present the most prosperous applications ranging from catalysis, through water purification and energy storage. Emphasis was given to materials that can be classified as green to the best in our consideration. As the summary, the current situation on developing hybrid materials as well as directions towards sustainable future using organic-inorganic hybrids are presented.

The intermetallic barium compounds BaTMg2 (T = Pd, Ag, Pt, Au) and BaAuCd2 were synthesized by reactions of the elements in sealed tantalum ampoules in muffle furnaces. The five compounds crystallize with the orthorhombic MgCuAl2 type structure, space group Cmcm, with small differences in chemical bonding between the magnesium and cadmium series. All samples were characterized through their Guinier powder diffraction patterns. The structures of BaPdMg2 (a = 444.57(4), b = 1174.67(10), c = 827.58(7) pm, wR2 = 0.0460, 475 F 2 values, 16 variables), BaAuMg2 (a = 450.27(6), b = 1183.94(16), c = 838.76(11) pm, wR2 = 0.0355, 473 F 2 values, 16 variables) and BaAuCd2 (a = 463.31(5), b = 1112.79(12), c = 826.63(8) pm, wR2 = 0.0453, 469 F 2 values, 16 variables) were refined from single crystal X-ray diffraction data. The large barium atoms push the [TMg2] respectively [AuCd2] substructures apart. This allows fast moisture attack and leads to fast hydrolyzes of the samples when they get in contact with water. The influence of the difference in electronegativity between magnesium and cadmium is reflected for the pair of compounds BaAuMg2 and BaAuCd2. The magnesium compound shows the higher auridic character, while the cadmium compound shows a tendency towards a three-dimensional cadmium substructure.

New and refined bond valence parameters related to ion pairs constituted of the tellurium Te4+ cation and non-oxide X n− anions (X = F, S or Se) are proposed. After a selection of specific crystalline structures, the optimization of the bond valence parameters R and b with a cutoff distance is carried out by minimizing the root mean square deviation of the Te4+ cation valence. The results are R = 1.728 Å and b = 0.622 Å with cutoff = 5.3 Å for the Te4+–F− pair and R = 2.444 Å and b = 0.387 Å with cutoff = 4.5 Å for the Te4+–S2− pair. These parameters lead to a lower dispersion of the calculated valences around the formal valence compared to that obtained with the parameters available in the literature. As for the new set related to the Te4+–Se2− pair, we find R = 2.578 Å and b = 0.296 Å with cutoff = 3.7 Å.

The cluster structure, thermochemical behavior, and some mechanisms of thermal decomposition of the crystalline products in the isodimorphic substitution series Cu x Ni(1−x)NTP (x = 0 … 1) have been studied by simultaneous the thermal gravimetric analysis and differential thermal analysis (TGA/DTA) and X-ray photoelectron spectroscopy (XPS). The complexes NiNTP and Cu1/8Ni7/8NTP with a monoclinic crystal structure are the most thermo-stable and characterized by one-step decomposition at 400–440 °C with the formation of metal phosphides and phosphates. The complexes Cu3/8Ni5/8NTP–Cu3/4Ni1/4NTP with the triclinic crystal lattice and the trigonal-bipyramidal coordination of metal atoms decompose in two steps. Firstly, the formation of a heteroligand complex with imino-bis-methylenephosphonic and methylphosphonic acids takes place at 245 °C. Secondly, the complex decomposes at 270–380 °C. The monometallic complex CuNTP decomposes almost completely at 280–300 °C.

There are reported two related structures of Ba5Mg4C54O48H114 (dodeca(aqua-6κ 3O,7κ 3O,8κ 3O,9κ 3O)-tris(μ2-propanoato-1:6κ 2O,1κO′)-tris(μ-propanoato-2:7κ 2O,2κO′-tris(μ-propanoato-3:8κ 2O,3κO′)-tris(μ-propanoato-4:9κ 2O,4κO′)-hexakis(μ3-propanoato-1:5κ 2O,2:5κ 2O′;1:5κ 2O,3:5κ 2O′;1:5κ 2O,4:5κ 2O′;2:5κ 2O,3:5κ 2O′;2:5κ 2O,4:5κ 2O′;3:5κ 2O,4:5κ 2O′)-pentabarium tetramagnesium), (I), and Pb5Mg4C54O48H114 (dodeca(aqua-1κ 3O,2κ 3O,3κ 3O,4κ 3O)-hexakis(μ3-propanoato-1:5κ 2O,2:5κ 2O′;1:5κ 2O,3:5κ 2O′;1:5 κ 2O,4:5κ 2O′;2:5κ 2O,3:5κ 2O′;2:5κ 2O,4:5κ 2O′;3:5κ 2O,4:5κ 2O′)tetramagnesium lead(II) tris(propanoato-κ 2O,O′)plumbate(II)), (II). The title structures are compositional isomers which crystallize in the same space group type. The structure of (I) comprises molecules with symmetry 4 ‾ 3 m $\overline{4}3m$ . The structure (II) comprises the complex cation {Pb(C3H5O2)6[Mg(H2O)3]4}4+ with the symmetry 4 ‾ 3 m $\overline{4}3m$ and four anions [tris(propanoato-κ 2O,O′)plumbate(II)]−, [Pb(C3H5O2)3]− , with 3m symmetry. The central cations Ba12+ and Pb12+ in (I) and in the cation {Pb(C3H5O2)6[Mg(H2O)3]4}4+ of the structure (II), respectively, have similar structural features which are comparable to the environment of the Ba2+ cation in BaCa2(C3H5O2)6 [Stadnicka, K. & Glazer, A. M. (1980). Acta Cryst. B36, 2977–2985]. The molecules in (I) and the ions in (II) are interconnected by Owater‒H⋯Opropanoate hydrogen bonds of a moderate strength. The ethyl chains are disordered which is common in propanoates. However, there are unprecedented features in the title structures: 1) The central atom Pb12+ is the first known example of a Pb2+ cation which is surrounded by six carboxylates in a bidentate bridging mode, i.e. by 12 oxygens. 2) The anion [tris(propanoato-κ 2O,O′)plumbate(II)]− has a constitution with unusually prominent stereochemical activity of the 6s 2 electron pair of the cation Pb2+ completing the coordination to the tetrahedral one. Thus, its formula can be expressed as [Pb[ψ−4t](C3H5O2)3]−. 3) In both title structures, there are propanoate molecules with disordered carboxylate oxygens.

In this work, two new perovskites of composition BaFe0.875Re0.125O3−δ and BaFe0.75Ta0.25O3−δ , designed from ab-initio calculations to fulfill different requisites of cathode materials for solid-oxide fuel cells (SOFC), were prepared and studied from the structural point of view from neutron powder diffraction (NPD) data. They are both derivatives of BaFeO3 hexagonal perovskite (space group P6 3 /mmc), typified as the 6H polytype, stabilized when the perovskite tolerance factor slightly overpasses the unity. Whereas BaFe0.875Re0.125O3−δ keeps this structural type, as demonstrated in this crystallographic study from NPD data at 295 and 4 K, with unit-cell parameters a = 5.70177(7); c = 14.0334(2) Å at 295 K, the second material, BaFe0.75Ta0.25O3−δ , is cubic and can be defined in the Pm-3m space group, corresponding of the perovskite arystotype, with a = 4.05876(3) Å. A conspicuous oxygen deficiency is observed, with a refined stoichiometry of 2.86(3) per formula unit. The anisotropic displacement factors for oxygen atoms in this last material are flattened disks perpendicular to the (Fe,Ta)-O-(Fe,Ta) direction, suggesting a dynamic tilting of the octahedra that could be related to the oxygen motion via oxygen vacancies across the structure. This is a pre-requisite for functional mixed-ionic-electronic (MIEC) materials performing as cathodes in SOFC.

The temperature dependences of the ionic electrical conductivity of fluorite-type (sp. gr. F m 3 ‾ m $Fm\overline{3}m$ , Z = 8) KDy3F10 and KHo3F10 single crystals grown by the Bridgman technique have been studied by impedance spectroscopy for the first time. The correlation between the conductometric and structural characteristics of KR 3F10 (R = Tb, Dy, Ho, Y) crystal family from the point of view of the observed size effect in the ionic conductivity is discussed. With decrease in the unit-cell volume V 1F per fluorine atom in a series of crystals with R = Tb, Dy, Ho and Y, the activation energy Eσ of ion transfer decreases from 1.57 to 1.16 eV respectively and the fluorine-ion conductivity value increases from 3.0 × 10−5 to 4.4 × 10−4 S cm at 773 K, i.e. the nature of the conductivity change is linearly antibatic. This phenomenon can be useful for developing approaches and search strategies for new ionic conductors.

The 1:1 co-crystals formed between 2-amino-5-chloropyridine/2-amino-5-bromopyridine and isomeric n-methyl-benzoic acids [n = 2, 3 and 4] are described. The co-crystals with the n = 2 co-former are isostructural. The co-formers are linked by intermolecular hydrogen bonds involving amino-N–H⋯O(carbonyl) and hydroxyl-O–H⋯N(pyridine). Additional and comparable amino-N–H⋯O(carbonyl) hydrogen bonds were evident in all co-crystals and play an important role in stabilising the molecular packing. The intermolecular interactions were also analysed through the calculated Hirshfeld surfaces. The charge transfer occurring between the calculated HOMO-LUMO states suggests electron mobility within the co-crystals owing to the aforementioned hydrogen bonding.

No scientific model has shaped crystallography as much as the classical nucleation theory (CNT). The majority of all growth processes and particle formation processes are attributed to the CNT. However, alternative descriptions exist that may be better suited to explain material formation under certain conditions. One of these alternatives is the dewetting theory (DWT). To describe the possibilities of DWT in more detail, we selected three material systems for three current application areas: Gold particles on silicon as catalysts for nanowire growth, indium particles on molybdenum as precursor material in novel solar cell concepts, and silicon layers on silicon germanium as potential wells in semiconductor quantum computers. Each of these material systems showed particular advantages of DWT over CNT. For example, the properties of surface particles with high atomic mobility could be described more realistically using DWT. Yet, there were clear indications that the DWT is not yet complete and that further research is needed to complete it. In particular, modern crystallographic challenges could serve this purpose, for example the development of semiconductor quantum computers, in order to re-evaluate known models such as the CNT and DWT and adapt them to the latest state of science and technology. For the time being, this article will give an outlook on the advantages of the DWT today and its potential for future research in crystallography.

Crystals of the first new organo–inorganic hybrid borate based on potassium crown ether complex, [K(C12H24O6)B5O6(OH)4](H2O) (1), have been produced from aqueous solutions and characterized by single-crystal X-ray diffraction. 1 crystalizes is orthorhombic system, Pnma, a = 10.1684(3) Å, b = 11.6289(3) Å, c = 21.2247(6) Å, V = 2509.76(12) Å3, R obs = 0.059. The structure of 1 consists of molecular [K(C12H24O6)B5O6(OH)4]0 complexes, common for crown ether complexes but yet not among borates, with a very rare monodentate coordination of the common pentaborate anion(1-). The molecular complexes are linked into weak chains via hydrogen bonding to outer-sphere water molecules. Hirshfeld surfaces analysis and complexity measurement of 1 were performed. Perspectives of borate structures containing crown ether complexes as templates are briefly outlined.

The crystal structure of the β-phase of Pigment Yellow 110 was determined from X-ray Powder Diffraction (XRPD) data. The crystal structure of the α-phase (Erk et al., CrystEngComm 2004, 6, 474) is re-refined against the original XRPD data to modern-day standards. Dispersion-corrected density functional theory calculations are used to complement the powder data. The α- and β-form crystallise in P 1 ‾ $P\overline{1}$ and P21/c, respectively, with the P.Y. 110 molecule occupying a centre of symmetry in both forms. Both polymorphs are layered structures consisting of infinite chains of hydrogen-bonded molecules.

Single crystals of the two alkali metal zinc oxidotellurates(IV), Rb2Zn(TeO3)(CO3)·H2O and Na2Zn2Te4O11, were obtained by reactions of mixtures of ZnO, TeO2, Rb2CO3 (molar ratios 2:3:6) and ZnO, TeO2, Na2CO3 (molar ratios 2:3:10), respectively, with small amounts of water as a mineralizer. Both compounds crystallize as order-disorder (OD) structures of layers and feature a high stacking fault probability. The crystal structure of Rb2Zn(TeO3)(CO3)·H2O is composed of layers extending parallel to (100). The structure is composed of two kinds of non-polar OD layers consisting of trigonal-pyramidal [TeO3]2−, tetrahedral [ZnO4]6−, Rb1+, and CO3 2−, H2O, Rb2+, respectively. Different centrings of the layer groups lead to an ambiguity in the stacking arrangement. The crystal structure of Na2Zn2Te4O11 is built from layers extending parallel to (001). Trigonal-pyramidal [TeO3]2− and bisphenoidal [TeO4]4− polyhedra form [Te4O11]6− groups, which are connected by longer Te–O-contacts to form 1 ∞[Te8O22]12− double chains oriented along either [100] or [010]. These chains form non-polar layers, which appear alternatingly in two orientations related by a fourfold rotoinversion. The Zn2+ and Na+ cations are located at the layer interface. The stacking ambiguity is due to different lattices of adjacent layers.

Group–subgroup schemes are a useful tool in crystal chemistry for systemizing crystal structures and they are an indispensable help during X-ray crystallographic studies of complex, twinned and modulated structures. Meanwhile many superstructure variants are summarized within so-called Bärnighausen trees. The present database lists relevant literature with respect to the crystallographic/group-theoretical tools and original work and gives a tabulated overview on the crystallographic fingerprints (aristotype, space group symbol, Pearson code and Wyckoff sequence) of the respective superstructures.