The title compound, 3-hydroxypropionitrile, was crystallized repeatedly in situ inside a quartz capillary using a liquid nitrogen cryostream. The X-ray powder diffraction patterns obtained indicated the presence of two distinct crystalline phases. The cleanest datasets for each of the phases were used to solve the crystal structures via simulated annealing, followed by refinement and optimization via dispersion-corrected density functional theory (DFT) calculations, with a final Rietveld refinement against the experimental data. The two structures appear to correspond to those proposed in a 1960s literature vibrational spectroscopy paper, one being the more stable with a gauche molecular conformation and the second metastable phase more complex with mixed conformations. Dispersion-corrected DFT computation using lattice parameters for both phases obtained from a single 84 K dataset with co-existing phases shows the stable and metastable phases to differ in energy by less than 0.5 kJ mol−1. A comparison of experimental far infrared spectra published in the 1960s with those calculated from the proposed crystal structures provides some independent supporting evidence for the proposed structures.

Dimethyl carbonate (DMC) is an important industrial solvent but is additionally a common component of liquid lithium-ion battery electrolytes. Pure DMC has a melting point of 277 K, so encountering solidification under outdoor climatic conditions is very likely in many locations around the globe. Even eutectic, ethylene carbonate:dimethyl carbonate commercial LiPF6 salt electrolyte formulations can start to solidify at temperatures around 260 K with obvious consequences for their performance. No structures for crystalline DMC are currently available which could be a hindrance for in situ battery studies at reduced temperatures. A time-of-flight neutron powder diffraction study of the phase behavior and crystal structures of deuterated DMC was undertaken to help fill this knowledge gap. Three different orthorhombic crystalline phases were found with a previously unreported low-temperature phase transition around 50–55 K. The progression of Pbca → Pbcm → Ibam space groups follow a sequence of group–subgroup relationships with the final Ibam structure being disordered around the central carbon atom.

The previously unreported crystal structure of (S)-Dapoxetine hydrochloride (DAPHCl), the only active pharmaceutical ingredient specially developed for the treatment of premature ejaculation in men, has been determined from laboratory X-ray powder diffraction data with DASH and refined by the Rietveld method with TOPAS-Academic. The structure was evaluated and optimized by dispersion-corrected DFT calculations. This compound crystallizes in an orthorhombic cell, space group P212121, with unit-cell parameters a= 6.3208(3) Å, b = 10.6681(5) Å, c = 28.1754(10) Å, V = 1899.89(14) Å3, Z = 4. The refinement converged to Rp = 0.0442, Rwp = 0.0577, and GoF = 2.440. The crystal structure is a complex 3D arrangement of DAPHCl moieties held together by hydrogen bonds, π⋯π, and C–H⋯π interactions. The chloride ions form layers parallel to the ab plane and are connected by dapoxetinium moieties through N–H⋯Cl and C–H⋯Cl hydrogen bonds. These layers stack along the c-axis, which are connected by C–H⋯π interactions. Hirshfeld surface analysis and fingerprint plot calculations have been performed.

Several benzothiophene-based compounds, including 1-benzothiophene-2-carboxylic acid, exhibit a wide variety of pharmacological activities. They have been extensively used to treat various types of diseases with high therapeutic effectiveness. In this contribution, the crystal structure of a new polymorph of 1-benzothiophene-2-carboxylic acid (BTCA) was determined from laboratory X-ray powder diffraction data with DASH, refined by the Rietveld method with TOPAS-Academic, and optimized using DFT-D calculations. The new form of 1-benzothiophene-2-carboxylic acid crystallizes in space group C2/c (No. 15) with a = 14.635(4), b = 5.8543(9), c = 19.347(3) Å, β = 103.95(1)°, V = 1608.8(6) Å3, and Z = 8. The structure is a complex 3D arrangement which can be described in terms of hydrogen-bonded dimers of BTCA molecules, joined by the acid–acid homosynthon, which interact through C–H⋯O hydrogen bonds to produce tapes further connected through head-to-tail π⋯π and edge-to-face C–H⋯π interactions. A comparison with a previously reported triclinic polymorph and with the related 1-benzofuran-2-carboxylic acid (BFCA) is also presented.

Arisite-(La), ideally NaLa2(CO3)2[F2x(CO3)1–x]F, is a new layered REE-fluorcarbonate mineral from miarolitic cavities within the Aris phonolite, Namibia (IMA no. 2009-019). It occurs as distinct chemical zones mixed with its Ce-analogue, arisite-(Ce). Crystals are vitreous, transparent beige, beige-yellow, light lemon-yellow to pinkish, and occur as tabular prisms up to 1.5 mm. Arisite-(La) is brittle, has conchoidal fracture, poor cleavage perpendicular to (001), a Mohs hardness of ~3–3½, is not fluorescent in either long- or shortwave UV radiation, dissolves slowly in dilute HCl at room temperature and sinks in methylene iodide, Dcalc. = 4.072 g cm–3. Arisite-(La) is uniaxial negative, has sharp extinction, with both ω and ε exhibiting a range of values within each grain: ω = 1.696–1.717(4) and ε = 1.594–1.611(3), a result of chemical zoning attributed to both Ce ⇌ La and Na ⇌ Ca substitutions. The crystal structure of both arisite-(Ce) and arisite-(La) were solved by direct methods and refined to R = 1.66%, wR2 = 4.31% (Ce) and R = 2.09%, wR2 = 5.26% (La), respectively. Arisite is hexagonal, Pm2, Z = 1, with unit-cell parameters of a = 5.1109(2) Å, c = 8.6713(4) Å, V = 196.16(6) Å3 for arisite-(Ce), and a = 5.1131(7) Å, c = 8.6759(17) Å, V = 196.43(5) Å3 for arisite-(La). Arisite-(Ce) and arisite-(La) are members of the layered, flat-lying REE-fluorcarbonate group which have crystal structures characterized by separate layers of triangular planar groups that parallel the overall layering of the structure, F, REE and alkali or alkaline-earthelements. Overall, the arisite structure can be defined by three distinct layers which parallel (001): (1) ∞[REE(CO3)2F] slabs, (2) sheets of Naϕ9 polyhedra, and (3) ∞[2F/CO3]2–. Based on its (M+F)/C ratio, arisite can further be described as having a dense, flat-lying fluorcarbonate structure, a classification which includes the structurally related mineral species cordylite, kukharenkoite, cebaite, lukechangite, huanghoite, and one incompletely characterized synthetic phase, NaY2(CO3)3F.

The crystal structure of chenevixite, Cu2M2(AsO4)2(OH)4 (where M = Fe3+ or Al), pseudo-orthorhombic, monoclinic, a = 5.7012(8), b = 5.1801(7), c = 29.265(2) Å, β = 89.99(1)°, V = 864.3(4) Å3, space group B1211, Z = 4, was solved by direct methods and refined by least-squares techniques to R = 8.4% and a goodness-of-fit (S) of 1.37 for 1176 unique observed (F≥4σF) reflections collected for a twinned microcrystal using graphite-monochromated Mo-Kα X-rays and a CCD area detector. Vertex- and edge-sharing arsenate tetrahedra, Alϕ6 octahedra, and Jahn-Teller-distorted Cu2+ϕ6 octahedra [ϕ: O2−;, (OH)−;] form a framework unique from those in Cu2+ oxysalt minerals. Chains of edge-sharing Cu2+ϕ6 octahedra, with Alϕ6 octahedra attached on opposing sides by the sharing of edges, are linked into layers parallel to (001) by sharing vertices with AsO4 tetrahedra, and the layers are linked to form a frameworkby the sharing of polyhedral elements between adjacent Alϕ6 octahedra, as well as between AsO4 tetrahedra and Alϕ6 octahedra.

The crystal structure of the spinel-related, Sb mineral tegengrenite from the Filipstad district, Värmland, Sweden, has been solved in the space group R3 [a = 16.0285(9), c = 14.8144(8) Å, V = 3296.1(3) Å3, Z = 42] and refined up to R = 0.0484 for 3589 reflections with Fo > 4σ(Fo). Tegengrenite exhibits a rhombohedrally distorted spinel-type structure with cations occupying 1/8 of the tetrahedral (T) and 1/2 of the octahedral (M) interstices of a nearly regular cubic close-packing of oxygen atoms. Due to the cation ordering, which leads to a complex superstructure with a unit-cell volume of 21/4 that of a common spinel, the M and T sites of the spinel-type structure split into ten and six independent sites, respectively. Chemical composition determined by electron microprobe led to the empirical formula Mg1.26Mn0.852+Zn0.04Mn0.193+Al0.01Si0.12Ti0.03Sb0.505+O4, on the assumption that no vacancies occur in the mineral (Σcat = 3.00 and Σcharge = 8.00 per formula unit). Crystal-chemical considerations indicate that octahedra are occupied mainly by Mg, Mn3+ and Sb5+ (+Al, + Ti), whereas tetrahedra are filled mainly by Mn2+ and Mg (+Zn) with Si ordered in a specific site. However, the structure refinement shows a low site-scattering factor for one octahedral site, implying substantial vacancies and a larger overall mean Mn valence than stated above. Long mean distances also suggest some Mn2+ on octahedral sites. Together, these observations necessitate the presence of substantial Mn3+ on tetrahedral sites.

The crystal structure and thermal expansion of the perovskite samarium cobalt oxide (SmCoO3) have been determined over the temperature range 295–1245 K by Rietveld analysis of X-ray powder diffraction data. Polycrystalline samples were prepared by a sol–gel synthesis route followed by high-temperature calcination in air. SmCoO3 is orthorhombic (Pnma) at all temperatures and is isostructural with GdFeO3. The structure was refined as a distortion mode of a parent $ Pm{\bar 3}m $ structure. The thermal expansion was found to be non-linear and anisotropic, with maximum average linear thermal expansion coefficients of 34.0(3) × 10−6, 24.05(17) × 10−6, and 24.10(18) × 10−6 K−1 along the a-, b-, and c-axes, respectively, between 814 and 875 K.

Crystal structures of two fused cyclic compounds, 4-(methyl(sulfonyl)methoxy-2-vinyl)-2S*,3aR*,4S*,5,7aS*-(hexahydro-1H-indan-3a-yl)methylmethanesulfonate (1) and (1S*,2S*,4S*,7R*)-7-(dimethyl(phenyl)silyl)-4′,5′-dihydro-2′H-spiro[bicyclo[2.2.1]hept[5]ene-2,3′-furan]-2′-one (2), have been solved from laboratory X-ray powder diffraction data using direct space approach and refined following the Rietveld method. In the absence of strong hydrogen bond donating groups, the crystal packing of 1 and 2 exhibits C–H ⋯ O hydrogen bonds and C–H ⋯ π interactions forming two-dimensional (2D) supramolecular network. The nature of intermolecular interactions in 1 and 2 has been analyzed through the Hirshfeld surface and 2D fingerprint plots. The density functional theory optimized molecular geometries in 1 and 2 agree closely with those obtained from the crystallographic study. Hirshfeld surface analysis of 1, 2 and a few related fused carbocyclic and carbooxacyclic systems retrieved from the Cambridge Structural Database indicates that about 85% of Hirshfeld surface area in these compounds are because of H ⋯ H and O ⋯ H interactions.

The Cambridge Structural Database (CSD) is a database of small molecule organic and organometallic crystal structures elucidated using X-Ray and neutron crystallography. The CSD is distributed alongside a system of software (the Cambridge Structural Database System) to academic and industrial users. The system contains a number of applications (in particular DASH, ConQuest, and Mogul) that can be used to aid crystallographers in the solution and refinement of crystal structures from powder diffraction data, and in the interpretation of crystal structure models (in particular, Mercury). This publication uses a racemic form of ornidazole (Z′ = 3) to illustrate the efficacy of DASH in the crystal structure solution from powder diffraction data. Furthermore, numerous features in Mogul and Mercury that aid crystal structure solution and interpretation of crystallographic data are revised. Finally, a review of a new method for using database-derived geometric information directly in structural solution is presented.

The crystal structure of the novel metal organic framework (MOF) Zn(C3H5NO2S)2 is described. This MOF can serve as a model for active sites in metalloproteins, on diverse activities such as structural or catalytic functions. Each half of the amino acid act as a bidentate ligand to one Zn and as a monodentate ligand to another Zn, while the disulphide bond presents an important structural function, stabilizing the crystal packing. The structure has been obtained ab initio from synchrotron X-ray powder diffraction data. The compound crystallizes in the orthorhombic system (space group P212121), with a = 20.0906(7), b = 9.5842(3), c = 5.018 89(13), and V = 966.40(5) Å3, with Z = 4. The structure was determined using a direct space approach, by means of the Monte Carlo technique, followed by Rietveld refinement.

Detailed procedures for solving small crystal structures ab initio with the maximum-entropy (ME) methods using X-ray powder diffraction data are described by determining the structure of the low-pressure phase of magnesium boron nitride, Mg3BN3(L), which was previously solved by one of the authors and co-workers using the Patterson method and the direct methods. The simple ME method devised by Gull, Livesey, and Sivia failed to correctly phase the structure-factor data, leading to noninterpretable electron-density maps. This method, maximizing the entropy under the constraints of the observed structure factors with subsequent incorporation of strong extrapolates in the basis set, trapped the solution in a local entropy maximum, from which there is no way to move. The multisolution method of phase determination by entropy maximization and likelihood evaluation, developed by Bricogne and Gilmore, successfully located all the Mg, B, and N atoms in one cycle of phase extension. The correct solution had a highest log-likelihood gain, but a minimum entropy, among the multisolutions generated by phase permutation.

In the framework of the study of the relationship between crystal packing of solid dyes and their visible reflectance spectra, the crystal structure of 3-methoxy-7H-benz[de]anthracen-7-one (Disperse Yellow 13, C18H12O2) has been determined using a combined set of Bragg–Brentano diffractometer and Guinier–Johannson photographic data with the grid search procedure. Parameters of the orthorhombic cell (P212121, No.19, Z=4) at 295 K are a=15.265(9) Å, b=20.524(9) Å, c=3.990(2) Å. Rietveld refinement gave Rp=0.085, Rb=0.135. The molecules form stacks along [001] with an interplanar spacing of 3.46 Å.

The structure of Ba7Cl2F12 has been determined ab initio from conventional X-ray powder diffraction data by the “heavy atom” method. The cell is hexagonal (space group P6¯, Z=1), with a=10.6373(2) Å and c=4.1724(2) Å. Refinement of 38 parameters by the Rietveld method, using 278 reflections, leads to cRwp=0.173, cRp=0.135, and RB=0.054. The structure has common characteristics with that of the other BaF2-rich fluorochloride, Ba12Cl5F19. In both phases Ba2+ ions lie in tricapped trigonal prisms formed by nine halide ions, and Cl− ions occupy the center of trigonal prisms of Ba2+ ions. F− ions are located in cationic tetrahedra or square pyramids.

Powder diffraction data for 2-aminophenalenone at 295 K (P21/n, Z=4) are given, strong lines: 7.54/X, 7.26/9, 3.34/3. The cell parameters found are a=3.7213(3), b=16.550(2), c=15.095(2) Å, β=92.61(2)°. The crystal structure was determined using powder data and refined giving Rb=0.089. Disordered molecules form stacks along [100] with interplanar spacing of 3.48 Å.

High-resolution powder X-ray diffraction and density functional plane wave pseudo-potential techniques have been used to obtain an optimized structural model of silver arachidate, [Ag(O2C(CH2)18CH3]2. The unit cell is triclinic, space group P-1 with cell dimensions of a = 4.1519(10) Å, b = 4.7055(10) Å, c = 53.555(4) Å, α = 89.473(15)°, β = 87.617(5)° and γ = 76.329(5)°. The structure is characterized by an 8-membered ring dimer of Ag atoms and carboxyl groups joined by four-member Ag–O rings with fully extended zigzag side chains, giving rise to one-dimensional chains along the b-axis.

The structure of the oxyphosphate Li0.50Ni0.25TiO(PO4) has been determined from conventional X-ray and neutron powder diffraction data. The parameters of the monoclinic cell (space group P21/c, Z=4), obtained from X-ray results, are: a=6.3954(6) Å, b=7.2599(6) Å, c=7.3700(5) Å, and β=90.266(6)°; those resulting from neutron study are: a=6.3906(7) Å, b=7.2568(7) Å, c=7.3673(9) Å, and β=90.234(7)°. Refinement by the Rietveld method using whole profile, leads to satisfactory reliability factors: cRwp=0.128, cRp=0.100, and RB=0.038 for X-ray and cRwp=0.110, cRp=0.120, and RB=0.060 for neutrons. The structure of Li0.50Ni0.25TiO(PO4) can be described as a TiOPO4 framework constituted by chains of tilted corner-sharing TiO6 octahedra running parallel to the c axis and cross linked by phosphate tetrahedra. In this framework, there are octahedral cavities occupied by Li and Ni atoms: Li occupies the totality of the 2a sites and Ni occupies statistically half of the 2b sites. Ti atoms are displaced from the center of octahedra units in alternating long (2.242 Å) and short (1.711 Å) Ti–O bonds along chains.

X-ray powder diffraction data for the anticancer drug PtCl2(C2H3O2)2(C6H13N)(NH3) are reported. The crystal structure of PtCl2(C2H3O2)2(C6H13N)(NH3) obtained from a Rietveld refinement are: space group P21/a, a=13.547(2) Å, b=8.260(1) Å, c=14.638(3) Å, β=110.429(2)°, V=1534.96 Å3, Z=4 and Dcalc.=2.068 Mg/m3.

The crystal structures of the chiolite-related room temperature phases α-Na5M3F14 (MIII=Cr,Fe,Ga) are determined. For all of them, the space group is P21/n, Z=2; a=10.5096(3) Å, b=7.2253(2) Å, c=7.2713(2) Å, β=90.6753(7)° (M=Cr); a=10.4342(7) Å, b=7.3418(6) Å, c=7.4023(6) Å, β=90.799(5)° (M=Fe), and a=10.4052(1) Å, b=7.2251(1) Å, c=7.2689(1), β=90.6640(4)° (M=Ga). Rietveld refinements produce final RF factors 0.036, 0.033, and 0.035, and RWP factors, 0.125, 0.116, and 0.096, for MIII=Cr, Fe, and Ga, respectively. The MF6 polyhedra in the defective isolated perovskite-like layers deviate very few from perfect octahedra. Subtle octahedra tiltings lead to the symmetry decrease from the P4/mnc space group adopted by the Na5Al3F14 chiolite aristotype to the P21/n space group adopted by the title series. Facile twinning precluded till now the precise characterization of these compounds.

The anhydrous acid strontium oxalate Sr(HC2O4)⋅½(C2O4) was obtained by thermal decomposition of the hydrated acid strontium oxalate Sr(HC2O4)⋅½(C2O4)⋅H2O. This non-hygroscopic compound crystallizes in the space group P 21/c (No. 14) with unit cell parameters: a=0.796 61(7) nm, b=0.9205(1) nm, c=0.731 98(8) nm, and β=102.104(8)°. Final refinement of the X-ray powder data yielded RB=3.2% and Rwp=11.1% (background-corrected data). In this structure, Sr is eight-fold coordinated by O. These polyhedra are connected together by edge-sharing to form two-dimensional (2D) layers along the bc-plane, which means that there is an increased dimensionality from 1D to 2D with decreasing water content of the acid oxalates.