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This study examines various methods for modelling the electron density and, thus, the electrostatic potential of an organometallic complex for use in crystal structure refinement against 3D electron diffraction (ED) data. It focuses on modelling the scattering factors of iron(III), considering the electron density distribution specific for coordination with organic linkers. We refined the structural model of the metal–organic complex, iron(III) acetylacetonate (FeAcAc), using both the independent atom model (IAM) and the transferable aspherical atom model (TAAM). TAAM refinement initially employed multipolar parameters from the MATTS databank for acetylacetonate, while iron was modelled with a spherical and neutral approach (TAAM ligand). Later, custom-made TAAM scattering factors for Fe—O coordination were derived from DFT calculations [TAAM-ligand-Fe(III)]. Our findings show that, in this compound, the TAAM scattering factor corresponding to Fe3+ has a lower scattering amplitude than the Fe3+ charged scattering factor described by IAM. When using scattering factors corresponding to the oxidation state of iron, IAM inaccurately represents electrostatic potential maps and overestimates the scattering potential of the iron. In addition, TAAM significantly improved the fitting of the model to the data, shown by improved R1 values, goodness-of-fit (GooF) and reduced noise in the Fourier difference map (based on the residual distribution analysis). For 3D ED, R1 values improved from 19.36% (IAM) to 17.44% (TAAM-ligand) and 17.49% (TAAM-ligand-Fe3+), and for single-crystal X-ray diffraction (SCXRD) from 3.82 to 2.03% and 1.98%, respectively. For 3D ED, the most significant R1 reductions occurred in the low-resolution region (8.65–2.00 Å), dropping from 20.19% (IAM) to 14.67% and 14.89% for TAAM-ligand and TAAM-ligand-Fe(III), respectively, with less improvement in high-resolution ranges (2.00–0.85 Å). This indicates that the major enhancements are due to better scattering modelling in low-resolution zones. Furthermore, when using TAAM instead of IAM, there was a noticeable improvement in the shape of the thermal ellipsoids, which more closely resembled those of an SCXRD-refined model. This study demonstrates the applicability of more sophisticated scattering factors to improve the refinement of metal–organic complexes against 3D ED data, suggesting the need for more accurate modelling methods and highlighting the potential of TAAM in examining the charge distribution of large molecular structures using 3D ED.

The antipsychotic drug olanzapine is well known for its complex polymorphism. Although widely investigated, the crystal structure of one of its anhydrous polymorphs, form III, is still unknown. Its appearance, always in concomitance with forms II and I, and the impossibility of isolating it from that mixture, have prevented its structure determination so far. The scenario has changed with the emerging field of 3D electron diffraction (3D ED) and its great advantages in the characterization of polyphasic mixtures of nanosized crystals. In this study, we show how the application of 3D ED allows the ab initio structure determination and dynamical refinement of this elusive crystal structure that remained unknown for more than 20 years. Olanzapine form III is monoclinic and shows a similar but shifted packing with respect to form II. It is remarkably different from the lowest-energy structures predicted by the energy-minimization algorithms of crystal structure prediction.

3D electron diffraction (3DED) is increasingly employed to determine molecular and crystal structures from micro-crystals. Indomethacin is a well known, marketed, small-molecule non-steroidal anti-inflammatory drug with eight known polymorphic forms, of which four structures have been elucidated to date. Using 3DED, we determined the structure of a new ninth polymorph, σ, found within an amorphous solid dispersion, a product formulation sometimes used for active pharmaceutical ingredients with poor aqueous solubility. Subsequently, we found that σ indomethacin can be produced from direct solvent evaporation using dichloromethane. These results demonstrate the relevance of 3DED within drug development to directly probe product formulations.

Although COF-300 is often used as an example to study the synthesis and structure of (3D) covalent organic frameworks (COFs), knowledge of the underlying synthetic processes is still fragmented. Here, an optimized synthetic procedure based on a combination of linker protection and modulation was applied. Using this approach, the influence of time and temperature on the synthesis of COF-300 was studied. Synthesis times that were too short produced materials with limited crystallinity and porosity, lacking the typical pore flexibility associated with COF-300. On the other hand, synthesis times that were too long could be characterized by loss of crystallinity and pore order by degradation of the tetrakis(4-aminophenyl)methane (TAM) linker used. The presence of the degradation product was confirmed by visual inspection, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). As TAM is by far the most popular linker for the synthesis of 3D COFs, this degradation process might be one of the reasons why the development of 3D COFs is still lagging compared with 2D COFs. However, COF crystals obtained via an optimized procedure could be structurally probed using 3D electron diffraction (3DED). The 3DED analysis resulted in a full structure determination of COF-300 at atomic resolution with satisfying data parameters. Comparison of our 3DED-derived structural model with previously reported single-crystal X-ray diffraction data for this material, as well as parameters derived from the Cambridge Structural Database, demonstrates the high accuracy of the 3DED method for structure determination. This validation might accelerate the exploitation of 3DED as a structure determination technique for COFs and other porous materials.

The charge‐transfer (CT) interactions between organic compounds are reflected in the (opto)electronic properties. Determining and visualizing crystal structures of CT complexes are essential for the design of functional materials with desirable properties. Complexes of pyranine (PYR), methyl viologen (MV), and their derivatives are the most studied water‐based CT complexes. Nevertheless, very few crystal structures of CT complexes have been reported so far. In this study, the structures of two PYRs‐MVs CT crystals and a map of the noncovalent interactions using 3D electron diffraction (3DED) are reported. Physical properties, e.g., band structure, conductivity, and electronic spectra of the CT complexes and their crystals are investigated and compared with a range of methods, including solid and liquid state spectroscopies and highly accurate quantum chemical calculations based on density functional theory (DFT). The combination of 3DED, spectroscopy, and DFT calculation can provide important insight into the structure‐property relationship of crystalline CT materials, especially for submicrometer‐sized crystals. [ABSTRACT FROM AUTHOR]

SnGe4N4O4 was synthesized at high pressure (16 and 20 GPa) and high temperature (1200 and 1500°C) in a large‐volume press. Powder X‐ray diffraction experiments using synchrotron radiation indicate that the derived samples are mixtures of known and unknown phases. However, the powder X‐ray diffraction patterns are not sufficient for structural characterization. Transmission electron microscopy studies reveal crystals of several hundreds of nanometres in size with different chemical composition. Among them, crystals of a previously unknown phase with stoichiometry SnGe4N4O4 were detected and investigated using automated diffraction tomography (ADT), a three‐dimensional electron diffraction method. Via ADT, the crystal structure could be determined from single nanocrystals in space group P63mc, exhibiting a nolanite‐type structure. This was confirmed by density functional theory calculations and atomic resolution scanning transmission electron microscopy images. In one of the syntheses runs a rhombohedral 6R polytype of SnGe4N4O4 could be found together with the nolanite‐type SnGe4N4O4. The structure of this polymorph was solved as well using ADT. [ABSTRACT FROM AUTHOR]

Dynamical refinement is a well established method for refining crystal structures against 3D electron diffraction (ED) data and its benefits have been discussed in the literature [Palatinus, Petříček & Corrêa, (2015). Acta Cryst. A71, 235–244; Palatinus, Corrêa et al. (2015). Acta Cryst. B71, 740–751]. However, until now, dynamical refinements have only been conducted using the independent atom model (IAM). Recent research has shown that a more accurate description can be achieved by applying the transferable aspherical atom model (TAAM), but this has been limited only to kinematical refinements [Gruza et al. (2020). Acta Cryst. A76, 92–109; Jha et al. (2021). J. Appl. Cryst. 54, 1234–1243]. In this study, we combine dynamical refinement with TAAM for the crystal structure of 1-methyluracil, using data from precession ED. Our results show that this approach improves the residual Fourier electrostatic potential and refinement figures of merit. Furthermore, it leads to systematic changes in the atomic displacement parameters of all atoms and the positions of hydrogen atoms. We found that the refinement results are sensitive to the parameters used in the TAAM modelling process. Though our results show that TAAM offers superior performance compared with IAM in all cases, they also show that TAAM parameters obtained by periodic DFT calculations on the refined structure are superior to the TAAM parameters from the UBDB/MATTS database. It appears that multipolar parameters transferred from the database may not be sufficiently accurate to provide a satisfactory description of all details of the electrostatic potential probed by the 3D ED experiment.

Znucalite is a zinc uranyl-carbonate mineral that was until recently only partially characterized with a formula originally given as Zn12Ca(UO2)(CO3)3(OH)22·4H2O, with an unknown crystal structure and ambiguous symmetry determinations. We have reinvestigated this mineral using three-dimensional electron diffraction (3D ED) and powder X-ray diffraction and revealed for the first time its structural details. Znucalite is unambiguously monoclinic, P21/m, with a = 10.722(2) Å, b = 6.259(1) Å, c = 25.355(1) Å, β = 101.13(1)°, and V = 1669.54(9) Å3. The structure refinement of the 3D ED data using the dynamical approach (Robs = 0.1594 for 3579 observed reflections and 244 parameters) provided the following structure model. Znucalite possesses a layered structure, with a [Zn10(OH)14(CO3)2] double sheet (with Zn2+ both in octahedra and tetrahedra), which is connected to a thick interlayer that hosts U6+, Ca2+, and H2O molecules. The linkage between structural units and the interlayer occurs via the vertices of ZnO4 tetrahedra protruding from the sheet. In the interlayer, differences in ordering between U and Ca take place and likely cause the difficulties encountered during the attempts to solve the structure. The refined structural formula of znucalite, Zn10Ca0.828[UO2]0.828[CO3]4(OH)15.312(H2O)5.484, corresponds well to the composition obtained from the electron-microprobe analyses, (Zn9.84Al0.16)Σ10.00 Ca0.83(UO2)0.80[(CO3)3.96(SO4)0.04]Σ4.00(OH)15.42(H2O)5.48. Raman spectroscopy evidenced the presence of several non-equivalent CO3 groups, as well as OH and H2O. The U-O bond lengths obtained from the stretching frequencies of U O 2 2 + vibrations are in line with the structural model. A discussion on the environmental importance of znucalite is appended, based on geochemical calculations with an estimate of the solubility product for this mineral. [ABSTRACT FROM AUTHOR]

Beauveriolides, including the main beauveriolide I {systematic name: (3R,6S,9S,13S)‐9‐benzyl‐13‐[(2S)‐hexan‐2‐yl]‐6‐methyl‐3‐(2‐methylpropyl)‐1‐oxa‐4,7,10‐triazacyclotridecane‐2,5,8,11‐tetrone, C27H41N3O5}, are a series of cyclodepsipeptides that have shown promising results in the treatment of Alzheimer's disease and in the prevention of foam cell formation in atherosclerosis. Their crystal structure studies have been difficult due to their tiny crystal size and fibre‐like morphology, until now. Recent developments in 3D electron diffraction methodology have made it possible to accurately study the crystal structures of submicron crystals by overcoming the problems of beam sensitivity and dynamical scattering. In this study, the absolute structure of beauveriolide I was determined by 3D electron diffraction. The cyclodepsipeptide crystallizes in the space group I2 with lattice parameters a = 40.2744 (4), b = 5.0976 (5), c = 27.698 (4) Å and β = 105.729 (6)°. After dynamical refinement, its absolute structure was determined by comparing the R factors and calculating the z‐scores of the two possible enantiomorphs of beauveriolide I. [ABSTRACT FROM AUTHOR]

Our study compares short-range order parameters refined from the diffuse scattering in single-crystal X-ray and single-crystal electron diffraction data. Nb0.84CoSb was chosen as a reference material. The correlations between neighbouring vacancies and the displacements of Sb and Co atoms were refined from the diffuse scattering using a Monte Carlo refinement in DISCUS. The difference between the Sb and Co displacements refined from the diffuse scattering and the Sb and Co displacements refined from the Bragg reflections in single-crystal X-ray diffraction data is 0.012 (7) Å for the refinement on diffuse scattering in single-crystal X-ray diffraction data and 0.03 (2) Å for the refinement on the diffuse scattering in single-crystal electron diffraction data. As electron diffraction requires much smaller crystals than X-ray diffraction, this opens up the possibility of refining short-range order parameters in many technologically relevant materials for which no crystals large enough for single-crystal X-ray diffraction are available.

Tetrakis‐4‐(4‐pyridyl)phenylmethane (TPPM) is a tetrahedral rigid molecule that crystallizes forming a dynamically responsive supramolecular organic framework (SOF). When exposed to different stimuli, this supramolecular network can reversibly switch from an empty to a filled solvated solid phase. This article describes a novel expanded form of a TPPM‐based SOF that has been mechanochemically synthesized and whose crystal structure has been determined by 3D electron diffraction analysis using a novel electron diffractometer. [ABSTRACT FROM AUTHOR]

Over 30 years ago, it was shown that bonding between atoms has a noticeable effect on convergent beam electron diffraction patterns. The paper by Olech et al. [(2024). IUCrJ, 11, 309–324] demonstrates that its influence is also clearly present in 3D electron diffraction data, opening up new possibilities for quantum crystallography.

Electron diffraction (known also as ED, 3D ED or microED) is gaining momentum in science and industry. The application of electron diffraction in performing nano-crystallography on crystals smaller than 1 µm is a disruptive technology that is opening up fascinating new perspectives for a wide variety of compounds required in the fields of chemical, pharmaceutical and advanced materials research. Electron diffraction enables the characterization of solid compounds complementary to neutron, powder X-ray and single-crystal X-ray diffraction, as it has the unique capability to measure nanometre-sized crystals. The recent introduction of dedicated instrumentation to perform ED experiments is a key aspect of the continued growth and success of this technology. In addition to the ultra-high-speed hybrid-pixel detectors enabling ED data collection in continuous rotation mode, a high-precision goniometer and horizontal layout have been determined as essential features of an electron diffractometer, both of which are embodied in the Eldico ED-1. Four examples of data collected on an Eldico ED-1 are showcased to demonstrate the potential and advantages of a dedicated electron diffractometer, covering selected applications and challenges of electron diffraction: (i) multiple reciprocal lattices, (ii) absolute structure of a chiral compound, and (iii) R-values achieved by kinematic refinement comparable to X-ray data.

Three-dimensional electron diffraction (3DED) from nanocrystals of biological macromolecules requires the use of very small crystals. These are typically less than 300 nm-thick in the direction of the electron beam due to the strong interaction between electrons and matter. In recent years, focused-ion-beam (FIB) milling has been used in the preparation of thin samples for 3DED. These instruments typically use a gallium liquid metal ion source. Inductively coupled plasma (ICP) sources in principle offer faster milling rates. Little work has been done to quantify the damage these sources cause to delicate biological samples at cryogenic temperatures. Here, an analysis of the effect that milling with plasma FIB (pFIB) instrumentation has on lysozyme crystals is presented. This work evaluates both argon and xenon plasmas and compares them with crystals milled with a gallium source. A milling protocol was employed that utilizes an overtilt to produce wedge-shaped lamellae with a shallow thickness gradient which yielded very thin crystalline samples. 3DED data were then acquired and standard data-processing statistics were employed to assess the quality of the diffraction data. An upper bound to the depth of the pFIB-milling damage layer of between 42.5 and 50 nm is reported, corresponding to half the thickness of the thinnest lamellae that resulted in usable diffraction data. A lower bound of between 32.5 and 40 nm is also reported, based on a literature survey of the minimum amount of diffracting material required for 3DED.

The new zeolite, COE-11, was synthesized at 155 °C to 168 °C by hydrothermal synthesis from a reaction mixture of SiO2/tetraethylammonium hydroxide/H3BO3/NaOH/H2O. Because tetraethylammonium is an unspecific structure directing agent, COE-11 crystallizes in all cases together with at least one impurity phase from a selection of phases: zeolite types *BEA, CHA, FER, MFI, MOR, MTW; the layered silicates magadiite and kenyaite; and searlsite and silica polymorph quartz. The crystal structure was solved from 3D electron diffraction (3D ED) data. Subsequent structure refinements of X-ray powder diffraction (PXRD) data and single crystal electron diffraction data converged to residual values of RF = 0.039, chi2 = 3.6 (PXRD) and RF = 21.81% (3D ED) confirming the structure model. COE-11 crystallizes in space group C2 with unit cell dimensions of a0 = 17.3494(11) Å, b0 = 17.3409(11) Å, c0 = 14.2789(4) Å and β = 113.762(2) °. The structure of COE-11 is characterized by a microporous borosilicate framework with intersecting, highly elliptical 12-ring channels running parallel (110) and (1–10) and forming a two-dimensional pore system. The Rietveld refinement provided a hint that boron partly substitutes silicon on three specific T sites of the framework. The idealized chemical composition of as-made COE-11 is [(CH3CH2)4N]4[B4Si62O132] per unit cell. Physico-chemical characterization using solid-state NMR spectroscopy, SEM, TG-DTA, and ATR-FTIR spectroscopy confirmed that COE-11 is a microporous borosilicate zeolite. COE-11 is structurally closely related to zeolite beta polymorph B but differs concerning the dimensionality of the pore system, which is 2D instead of 3D.

Levocetirizine is an orally administrated, second‐generation antihistaminic active pharmaceutical ingredient that has been used to treat symptoms of allergy and long‐term hives for over 25 years. Despite the wide use of this compound, its crystal structure has remained unknown. Here we report the application of 3D electron diffraction (3D ED)/Micro‐crystal electron diffraction (MicroED) to determine the crystal structure of Levocetirizine dihydrochloride directly from crystalline powders that were extracted from commercially available tablets containing the compound. We also showcase the utility of dynamical refinement to unambiguously assign absolute configuration. The results highlight the immense potential of 3D ED/MicroED for structure elucidation of components of microcrystalline mixtures that obviates the need to grow large‐size single crystals and the use of complementary analytical techniques, which could be important for identification as well as for primary structural characterization. [ABSTRACT FROM AUTHOR]

The new zeolite, COE-11, was synthesized at 155 °C to 168 °C by hydrothermal synthesis from a reaction mixture of SiO2/tetraethylammonium hydroxide/H3BO3/NaOH/H2O. Because tetraethylammonium is an unspecific structure directing agent, COE-11 crystallizes in all cases together with at least one impurity phase from a selection of phases: zeolite types *BEA, CHA, FER, MFI, MOR, MTW; the layered silicates magadiite and kenyaite; and searlsite and silica polymorph quartz. The crystal structure was solved from 3D electron diffraction (3D ED) data. Subsequent structure refinements of X-ray powder diffraction (PXRD) data and single crystal electron diffraction data converged to residual values of RF = 0.039, chi2 = 3.6 (PXRD) and RF = 21.81% (3D ED) confirming the structure model. COE-11 crystallizes in space group C2 with unit cell dimensions of a0 = 17.3494(11) Å, b0 = 17.3409(11) Å, c0 = 14.2789(4) Å and β = 113.762(2) °. The structure of COE-11 is characterized by a microporous borosilicate framework with intersecting, highly elliptical 12-ring channels running parallel (110) and (1–10) and forming a two-dimensional pore system. The Rietveld refinement provided a hint that boron partly substitutes silicon on three specific T sites of the framework. The idealized chemical composition of as-made COE-11 is [(CH3CH2)4N]4[B4Si62O132] per unit cell. Physico-chemical characterization using solid-state NMR spectroscopy, SEM, TG-DTA, and ATR-FTIR spectroscopy confirmed that COE-11 is a microporous borosilicate zeolite. COE-11 is structurally closely related to zeolite beta polymorph B but differs concerning the dimensionality of the pore system, which is 2D instead of 3D. [ABSTRACT FROM AUTHOR]

The true molecular conformation and the crystal structure of benzo[e]dinaphtho[2,3-a;1′,2′,3′,4′-ghi]fluoranthene, 7,14-diphenylnaphtho[1,2,3,4-cde]bisanthene and 7,16-diphenylnaphtho[1,2,3,4-cde]helianthrene were determined ab initio by 3D electron diffraction. All three molecules are remarkable polycyclic aromatic hydrocarbons. The molecular conformation of two of these compounds could not be determined via classical spectroscopic methods due to the large size of the molecule and the occurrence of multiple and reciprocally connected aromatic rings. The molecular structure of the third molecule was previously considered provisional. These compounds were isolated as by-products in the synthesis of similar products and were at the same time nanocrystalline and available only in very limited amounts. 3D electron diffraction data, taken from submicrometric single crystals, allowed for direct ab initio structure solution and the unbiased determination of the internal molecular conformation. Detailed synthetic routes and spectroscopic analyses are also discussed. Based on many-body perturbation theory simulations, benzo[e]dinaphtho[2,3-a;1′,2′,3′,4′-ghi]fluoranthene may be a promising candidate for triplet–triplet annihilation and 7,14-diphenylnaphtho[1,2,3,4-cde]bisanthene may be a promising candidate for intermolecular singlet fission in the solid state.

Recent interest in structure solution and refinement using electron diffraction (ED) has been fuelled by its inherent advantages when applied to crystals of sub-micrometre size, as well as its better sensitivity to light elements. Currently, data are often processed with software written for X-ray diffraction, using the kinematic theory of diffraction to generate model intensities – despite the inherent differences in diffraction processes in ED. Here, dynamical Bloch-wave simulations are used to model continuous-rotation electron diffraction data, collected with a fine angular resolution (crystal orientations of ∼0.1°). This fine-sliced data allows a re-examination of the corrections applied to ED data. A new method is proposed for optimizing crystal orientation, and the angular range of the incident beam and the varying slew rate are taken into account. Observed integrated intensities are extracted and accurate comparisons are performed with simulations using rocking curves for a (110) lamella of silicon 185 nm thick. R1 is reduced from 26% with the kinematic model to 6.8% using dynamical simulations.

Determination of lattice parameters from 3D electron diffraction (3D ED) data measured in a transmission electron microscope is hampered by a number of effects that seriously limit the achievable accuracy. The distortion of the diffraction patterns by the optical elements of the microscope is often the most severe problem. A thorough analysis of a number of experimental datasets shows that, in addition to the well known distortions, namely barrel-pincushion, spiral and elliptical, an additional distortion, dubbed parabolic, may be observed in the data. In precession electron diffraction data, the parabolic distortion leads to excitation-error-dependent shift and splitting of reflections. All distortions except for the elliptical distortion can be determined together with lattice parameters from a single 3D ED data set. However, the parameters of the elliptical distortion cannot be determined uniquely due to correlations with the lattice parameters. They can be determined and corrected either by making use of the known Laue class of the crystal or by combining data from two or more crystals. The 3D ED data can yield lattice parameter ratios with an accuracy of about 0.1% and angles with an accuracy better than 0.03°.

In contrast to perfectly periodic crystals, materials with short-range order produce diffraction patterns that contain both Bragg reflections and diffuse scattering. To understand the influence of short-range order on material properties, current research focuses increasingly on the analysis of diffuse scattering. This article verifies the possibility to refine the short-range order parameters in submicrometre-sized crystals from diffuse scattering in single-crystal electron diffraction data. The approach was demonstrated on Li1.2Ni0.13Mn0.54Co0.13O2, which is a state-of-the-art cathode material for lithium-ion batteries. The intensity distribution of the 1D diffuse scattering in the electron diffraction patterns of Li1.2Ni0.13Mn0.54Co0.13O2 depends on the number of stacking faults and twins in the crystal. A model of the disorder in Li1.2Ni0.13Mn0.54Co0.13O2 was developed and both the stacking fault probability and the percentage of the different twins in the crystal were refined using an evolutionary algorithm in DISCUS. The approach was applied on reciprocal space sections reconstructed from 3D electron diffraction data since they exhibit less dynamical effects compared with in-zone electron diffraction patterns. A good agreement was achieved between the calculated and the experimental intensity distribution of the diffuse scattering. The short-range order parameters in submicrometre-sized crystals can thus successfully be refined from the diffuse scattering in single-crystal electron diffraction data using an evolutionary algorithm in DISCUS.

The crystallographic study of two polymorphs of the industrial pyrazolone Pigment Orange 13 (P.O.13) is reported. The crystal structure of the β phase was determined using single‐crystal X‐ray analysis of a tiny needle. The α phase was investigated using three‐dimensional electron diffraction. The electron diffraction data contain sharp Bragg reflections and strong diffuse streaks, associated with severe stacking disorder. The structure was solved by careful analysis of the diffuse scattering, and similarities of the unit‐cell parameters with the β phase. The structure solution is described in detail and this provides a didactic example of solving molecular crystal structures in the presence of diffuse scattering. Several structural models were constructed and optimized by lattice‐energy minimization with dispersion‐corrected DFT. A four‐layer model was found, which matches the electron diffraction data, including the diffuse scattering, and agrees with X‐ray powder data. Additionally, five further phases of P.O.13 are described. [ABSTRACT FROM AUTHOR]

Electron diffraction (known also as ED, 3D ED or microED) is gaining momentum in science and industry. The application of electron diffraction in performing nano-crystallography on crystals smaller than 1 mm is a disruptive technology that is opening up fascinating new perspectives for a wide variety of compounds required in the fields of chemical, pharmaceutical and advanced materials research. Electron diffraction enables the characterization of solid compounds complementary to neutron, powder X-ray and single-crystal X-ray diffraction, as it has the unique capability to measure nanometre-sized crystals. The recent introduction of dedicated instrumentation to perform ED experiments is a key aspect of the continued growth and success of this technology. In addition to the ultra-high-speed hybrid-pixel detectors enabling ED data collection in continuous rotation mode, a high-precision goniometer and horizontal layout have been determined as essential features of an electron diffractometer, both of which are embodied in the Eldico ED-1. Four examples of data collected on an Eldico ED-1 are showcased to demonstrate the potential and advantages of a dedicated electron diffractometer, covering selected applications and challenges of electron diffraction: (i) multiple reciprocal lattices, (ii) absolute structure of a chiral compound, and (iii) R-values achieved by kinematic refinement comparable to X-ray data. [ABSTRACT FROM AUTHOR]

The crystallographic study of two polymorphs of the industrial pyrazolone Pigment Orange 13 (P.O.13) is reported. The crystal structure of the β phase was determined using single‐crystal X‐ray analysis of a tiny needle. The α phase was investigated using three‐dimensional electron diffraction. The electron diffraction data contain sharp Bragg reflections and strong diffuse streaks, associated with severe stacking disorder. The structure was solved by careful analysis of the diffuse scattering, and similarities of the unit‐cell parameters with the β phase. The structure solution is described in detail and this provides a didactic example of solving molecular crystal structures in the presence of diffuse scattering. Several structural models were constructed and optimized by lattice‐energy minimization with dispersion‐corrected DFT. A four‐layer model was found, which matches the electron diffraction data, including the diffuse scattering, and agrees with X‐ray powder data. Additionally, five further phases of P.O.13 are described. [ABSTRACT FROM AUTHOR]

Three‐dimensional electron diffraction (3D ED) has become an effective technique to determine the structures of submicrometre‐ (nanometre‐)sized crystals. In this work, energy‐filtered 3D ED was implemented using a post‐column energy filter in both STEM mode and TEM mode [(S)TEM denoting (scanning) transmission electron microscope]. The setups for performing energy‐filtered 3D ED on a Gatan imaging filter are described. The technique and protocol improve the accessibility of energy‐filtered 3D ED post‐column energy filters, which are available in many TEM laboratories. In addition, a crystal tracking method in STEM mode using high‐angle annular dark‐field imaging is proposed. This method enables the user to monitor the crystal position while collecting 3D ED data at the same time, allowing a larger tilt range without foregoing any diffraction frames or imposing extra electron dose. In order to compare the differences between energy‐filtered and unfiltered 3D ED data sets, three well known crystallized inorganic samples have been studied in detail. For these samples, the final R1 values improved by 10–30% for the energy‐filtered data sets compared with the unfiltered data sets, and the structures became more chemically reasonable. Possible reasons for improvement are also discussed. [ABSTRACT FROM AUTHOR]

• Diffuse scattering data used for quantitative analysis can best be acquired in selected area electron diffraction (SAED) mode using a CCD and an energy filter. • The three-dimensional diffuse scattering in three-dimensional electron diffraction (3D ED) data can be obtained with a quality comparable to that from single-crystal X-ray diffraction. • For quantitative analysis of the diffuse scattering, 3D ED data should be acquired rather than in-zone SAED or in-zone precession electron diffraction (PED) patterns. The diffraction patterns of crystalline materials with local order contain sharp Bragg reflections as well as highly structured diffuse scattering. In this study, we quantitatively show how the diffuse scattering in three-dimensional electron diffraction (3D ED) data is influenced by various parameters, including the data acquisition mode, the detector type and the use of an energy filter. We found that diffuse scattering data used for quantitative analysis are preferably acquired in selected area electron diffraction (SAED) mode using a CCD and an energy filter. In this study, we also show that the diffuse scattering in 3D ED data can be obtained with a quality comparable to that from single-crystal X-ray diffraction. As electron diffraction requires much smaller crystal sizes than X-ray diffraction, this opens up the possibility to investigate the local structure of many technologically relevant materials for which no crystals large enough for single-crystal X-ray diffraction are available. [ABSTRACT FROM AUTHOR]

Grandviewite is redefined on the basis of a reinvestigation of the holotype specimen from the Grandview mine, Arizona, USA, and additional specimens found in the Restauradora vein at the Capillitas mine, northwestern Argentina. Grandviewite from the Capillitas mine forms globular masses up to a couple of millimetres in diameter, formed by very thin platy to acicular lath-like crystals, greenish-pale blue in colour, pleochroic (X = colourless, Y = very pale blue and Z = greenish-pale blue), with pale blue streak and silky to a satiny lustre. Results of an electron-microprobe study and crystal-structure determination lead to the new ideal formula Cu3Al2(SO4)(OH)10⋅H2O, which requires (in wt.%) CuO 45.13, Al2O3 19.28, SO3 15.14, and H2O 20.45, total 100.00. Its empirical formulas are (Cu2.96Mn0.01)Σ2.97Al2.03(SO4)0.97(SiO4)0.03(AsO4)0.01(OH)9.97Cl0.01⋅H2O (Grandview mine) and Cu2.97(Al2.03Fe0.01)Σ2.04(SO4)0.95(SiO4)0.03(AsO4)0.01(PO4)0.01(OH)9.97Cl0.01⋅H2O (Capillitas mine). Grandviewite is triclinic, P $\bar{1}$ , with unit-cell parameters refined from powder X-ray diffraction data: a = 5.713(2), b = 10.1374(8), c = 10.9791(9) Å, α = 72.240(6)°, β = 82.79(2)°, γ = 86.07(2)°, V = 600.5(3) Å3 and Z = 2 (Grandview mine); and a = 5.749(3), b = 10.1388(13), c = 10.9656(16) Å, α = 72.344(1)°, β = 82.83(4)°, γ = 86.77(3)°, V = 604.2(3) Å3 and Z = 2 (Capillitas mine). The crystal structure of grandviewite from the Capillitas mine was solved by 3-dimensional electron diffraction analysis (R(obs)/wR(obs) = 0.1304/0.1316 for 6401/31007 observed reflections with I ≥ 3σ(I). Grandviewite contains infinite AlO6–Cu1–AlO6 slabs along a connected on both ends to Cu2 [4 + 1]–SO4 chains. The SO4 tetrahedra form a disordered chain along a connected to the Cu2 pyramids on one side and are otherwise stabilised by strong hydrogen bonds to surrounding units. The Raman and infrared spectra for samples from both occurrences are identical. The redefinition (new chemical formula and triclinic symmetry) has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (number 21-K). [ABSTRACT FROM AUTHOR]

Uranotungstite is an uranyl-tungstate mineral that was until recently only partially characterized with a formula originally given as (Fe2+,Ba,Pb)(UO2)2(WO4)(OH)4·12H2O and an unknown crystal structure. This mineral has been reinvestigated by electron microprobe analysis coupled with three-dimensional electron diffraction. According to the electron microprobe data, the holotype material from the Menzenschwand uranium deposit (Black Forest, Germany) has the empirical formula (Ba0.35Pb0.27)Σ0.62[(U6+O2)2(W60.98+ Fe30.26+ ◻0.75)O4.7(OH)2.5(H2O)1.75](H2O)1.67 (average of 8 points calculated on the basis of 2U apfu; H2O content derived from the structure). According to the precession-assisted 3D ED data, holotype uranotungstite from Menzenschwand is monoclinic, P21/m, with a = 6.318(5) Å, b = 7.388(9) Å, c = 13.71(4) Å, β = 99.04(13)°, and V = 632(2) Å3 (Z = 2). The structure refinement of the 3D ED data using the dynamical approach (Robs = 0.0846 for 3287 independent observed reflections) provided a structure model composed of heteropolyhedral sheets. A β-U3O8-type sheet of idealized composition [(UO2)2W6+Fe30.25+ ◻0.75O4.75(OH)1.5(H2O)1.75]0.25– is composed of UO7 polyhedra linked by (W,Fe)O5 polyhedra in which the W:Fe ratio is variable as well as the bulk occupancy of this site; the W site may also host a minor proportion of Cu, Mg, or V. In uranotungstite, the interlayer spaces between adjacent U-W-O sheets host water on one side and, on the other side, a partially occupied cation site mostly occupied by Ba and, to a lesser extent, Pb, as well as a partially occupied H2O site. This work is the first structural description of a natural uranyl-tungstate mineral and confirms the great structural and chemical flexibility of β-U3O8 type of sheets. [ABSTRACT FROM AUTHOR]

Nanomedicine is among the most fascinating areas of research. Most of the newly discovered pharmaceutical polymorphs, as well as many new synthesized or isolated natural products, appear only in form of nanocrystals. The development of techniques that allow investigating the atomic structure of nanocrystalline materials is therefore one of the most important frontiers of crystallography. Some unique features of electrons, like their non‐neutral charge and their strong interaction with matter, make this radiation suitable for imaging and detecting individual atoms, molecules, or nanoscale objects down to sub‐angstrom resolution. In the recent years the development of three‐dimensional (3D) electron diffraction (3D ED) has shown that electron diffraction can be successfully used to solve the crystal structure of nanocrystals and most of its limiting factors like dynamical scattering or limited completeness can be easily overcome. This article is a review of the state of the art of this method with a specific focus on how it can be applied to beam sensitive samples like small‐molecule organic nanocrystals. This article is categorized under:Therapeutic Approaches and Drug Discovery > Emerging Technologies [ABSTRACT FROM AUTHOR]

The antipsychotic drug olanzapine is well known for its complex polymorphism. Although widely investigated, the crystal structure of one of its anhydrous polymorphs, form III, is still unknown. Its appearance, always in concomitance with forms II and I, and the impossibility of isolating it from that mixture, have prevented its structure determination so far. The scenario has changed with the emerging field of 3D electron diffraction (3D ED) and its great advantages in the characterization of polyphasic mixtures of nanosized crystals. In this study, we show how the application of 3D ED allows the ab initio structure determination and dynamical refinement of this elusive crystal structure that remained unknown for more than 20 years. Olanzapine form III is monoclinic and shows a similar but shifted packing with respect to form II. It is remarkably different from the lowest-energy structures predicted by the energy-minimization algorithms of crystal structure prediction., (open access.)

3D electron diffraction (3DED) is increasingly employed to determine molecular and crystal structures from micro-crystals. Indomethacin is a well known, marketed, small-molecule non-steroidal anti-inflammatory drug with eight known polymorphic forms, of which four structures have been elucidated to date. Using 3DED, we determined the structure of a new ninth polymorph, σ, found within an amorphous solid dispersion, a product formulation sometimes used for active pharmaceutical ingredients with poor aqueous solubility. Subsequently, we found that σ indomethacin can be produced from direct solvent evaporation using dichloromethane. These results demonstrate the relevance of 3DED within drug development to directly probe product formulations., (open access.)

This study examines various methods for modelling the electron density and, thus, the electrostatic potential of an organometallic complex for use in crystal structure refinement against 3D electron diffraction (ED) data. It focuses on modelling the scattering factors of iron(III), considering the electron density distribution specific for coordination with organic linkers. We refined the structural model of the metal-organic complex, iron(III) acetylacetonate (FeAcAc), using both the independent atom model (IAM) and the transferable aspherical atom model (TAAM). TAAM refinement initially employed multipolar parameters from the MATTS databank for acetylacetonate, while iron was modelled with a spherical and neutral approach (TAAM ligand). Later, custom-made TAAM scattering factors for Fe-O coordination were derived from DFT calculations [TAAM-ligand-Fe(III)]. Our findings show that, in this compound, the TAAM scattering factor corresponding to Fe 3+ has a lower scattering amplitude than the Fe 3+ charged scattering factor described by IAM. When using scattering factors corresponding to the oxidation state of iron, IAM inaccurately represents electrostatic potential maps and overestimates the scattering potential of the iron. In addition, TAAM significantly improved the fitting of the model to the data, shown by improved R 1 values, goodness-of-fit (GooF) and reduced noise in the Fourier difference map (based on the residual distribution analysis). For 3D ED, R 1 values improved from 19.36% (IAM) to 17.44% (TAAM-ligand) and 17.49% (TAAM-ligand-Fe 3+ ), and for single-crystal X-ray diffraction (SCXRD) from 3.82 to 2.03% and 1.98%, respectively. For 3D ED, the most significant R 1 reductions occurred in the low-resolution region (8.65-2.00 Å), dropping from 20.19% (IAM) to 14.67% and 14.89% for TAAM-ligand and TAAM-ligand-Fe(III), respectively, with less improvement in high-resolution ranges (2.00-0.85 Å). This indicates that the major enhancements are due to better scattering modelling in low-resolution zones. Furthermore, when using TAAM instead of IAM, there was a noticeable improvement in the shape of the thermal ellipsoids, which more closely resembled those of an SCXRD-refined model. This study demonstrates the applicability of more sophisticated scattering factors to improve the refinement of metal-organic complexes against 3D ED data, suggesting the need for more accurate modelling methods and highlighting the potential of TAAM in examining the charge distribution of large molecular structures using 3D ED., (open access.)

Time-resolved carbamazepine crystallization from wet ethanol has been monitored using a combination of cryoTEM and 3D electron diffraction. Carbamazepine is shown to crystallize exclusively as a dihydrate after 180 s. When the timescale was reduced to 30 s, three further polymorphs could be identified. At 20 s, the development of early stage carbamazepine dihydrate was observed through phase separation. This work reveals two possible crystallization pathways present in this active pharmaceutical ingredient.

Kaatialaite mineral Fe[AsO2(OH)2]5H2O from Jáchymov, Czech Republic forms white aggregates of needle-shaped crystals with micrometric size. Its structure at ambient temperature has already been reported but hydrogen atoms could not be identified from single-crystal X-ray diffraction. An analysis using 3D electron diffraction at low temperature brings to light the hydrogen positions and the existence of hydrogen disorder. At 100 K, kaatialaite is described in a monoclinic unit cell of a = 15.46, b = 19.996, c = 4.808 Å, β = 91.64° and V = 1485.64 Å3 with space group P21/n. The hydrogen sites were revealed after refinements both considering the dynamical effects and ignoring them. The possibility to access most of the hydrogen positions, including partially occupied ones among heavy atoms, from the kinematical refinement is due to the recent developments in the analysis of 3D electron data. The hydrogen bonding observed in kaatialaite provides examples of H2O configurations that have not been observed before in the structures of oxysalts with the presence of unusual inverse transformer H2O groups.

A glass ceramic from the MgO–Al 2 O 3 –SiO 2 system containing additives of ZrO 2 , TiO 2 , La 2 O 3 and P 2 O 5 was investigated. Via x-ray powder diffraction (XRPD) and Transmission electron microscopy(TEM) the crystalline phases present could be identified as MgAl 2 O 4 (Spinel), orthorhombic ZrTiO 4 and a polymorph of LaPO 4 with a previously unknown crystal structure. The crystal structure of this LaPO 4 phase was solved ab initio via 3D ED Data. The polymorph occurs in a distorted barite structure type in the same space group (P2 1 /n) as the stable monazite type polymorph, however the density is higher and the La has a higher coordination number. Furthermore the LaPO 4 is present in a spinodal relict microstructure. Potential explanations for the presence of this metastable polymorph are pressure due to residual stresses from the crystallization or surface effects due to the high surface area resulting from the spinodal relict structure. [ABSTRACT FROM AUTHOR]

This study made use of a recently developed combination of advanced methods to reveal the atomic structure of a disordered nanocrystalline zeolite using exit wave reconstruction, automated diffraction tomography, disorder modelling and diffraction pattern simulation. By applying these methods, it was possible to determine the so far unknown structures of the hydrous layer silicate RUB-6 and the related zeolite-like material RUB-5. The structures of RUB-5 and RUB-6 contain the same dense layer-like building units (LLBUs). In the case of RUB-5, these building units are interconnected via additional SiO4/2 tetrahedra, giving rise to a framework structure with a 2D pore system consisting of intersecting 8-ring channels. In contrast, RUB-6 contains these LLBUs as separate silicate layers terminated by silanol/siloxy groups. Both RUB-6 and RUB-5 show stacking disorder with intergrowths of different polymorphs. The unique structure of RUB-6, together with the possibility for an interlayer expansion reaction to form RUB-5, make it a promising candidate for interlayer expansion with various metal sources to include catalytically active reaction centres.

Although COF-300 is often used as an example to study the synthesis and structure of (3D) covalent organic frameworks (COFs), knowledge of the underlying synthetic processes is still fragmented. Here, an optimized synthetic procedure based on a combination of linker protection and modulation was applied. Using this approach, the influence of time and temperature on the synthesis of COF-300 was studied. Synthesis times that were too short produced materials with limited crystallinity and porosity, lacking the typical pore flexibility associated with COF-300. On the other hand, synthesis times that were too long could be characterized by loss of crystallinity and pore order by degradation of the tetrakis(4-aminophenyl)methane (TAM) linker used. The presence of the degradation product was confirmed by visual inspection, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). As TAM is by far the most popular linker for the synthesis of 3D COFs, this degradation process might be one of the reasons why the development of 3D COFs is still lagging compared with 2D COFs. However, COF crystals obtained via an optimized procedure could be structurally probed using 3D electron diffraction (3DED). The 3DED analysis resulted in a full structure determination of COF-300 at atomic resolution with satisfying data parameters. Comparison of our 3DED-derived structural model with previously reported single-crystal X-ray diffraction data for this material, as well as parameters derived from the Cambridge Structural Database, demonstrates the high accuracy of the 3DED method for structure determination. This validation might accelerate the exploitation of 3DED as a structure determination technique for COFs and other porous materials., (open access.)

SnGe 4 N 4 O 4 was synthesized at high pressure (16 and 20 GPa) and high temperature (1200 and 1500°C) in a large-volume press. Powder X-ray diffraction experiments using synchrotron radiation indicate that the derived samples are mixtures of known and unknown phases. However, the powder X-ray diffraction patterns are not sufficient for structural characterization. Transmission electron microscopy studies reveal crystals of several hundreds of nanometres in size with different chemical composition. Among them, crystals of a previously unknown phase with stoichiometry SnGe 4 N 4 O 4 were detected and investigated using automated diffraction tomography (ADT), a three-dimensional electron diffraction method. Via ADT, the crystal structure could be determined from single nanocrystals in space group P6 3 mc, exhibiting a nolanite-type structure. This was confirmed by density functional theory calculations and atomic resolution scanning transmission electron microscopy images. In one of the syntheses runs a rhombohedral 6R polytype of SnGe 4 N 4 O 4 could be found together with the nolanite-type SnGe 4 N 4 O 4 . The structure of this polymorph was solved as well using ADT., (open access.)

Copper perchlorophthalocyanine (CuPcCl16, CuC32N8Cl16, Pigment Green 7) is one of the commercially most important green pigments. The compound is a nanocrystalline fully insoluble powder. Its crystal structure was first addressed by electron diffraction in 1972 [Uyeda et al. (1972). J. Appl. Phys.43, 5181–5189]. Despite the commercial importance of the compound, the crystal structure remained undetermined until now. Using a special vacuum sublimation technique, micron‐sized crystals could be obtained. Three‐dimensional electron diffraction (3D ED) data were collected in two ways: (i) in static geometry using a combined stage‐tilt/beam‐tilt collection scheme and (ii) in continuous rotation mode. Both types of data allowed the crystal structure to be solved by direct methods. The structure was refined kinematically with anisotropic displacement parameters for all atoms. Due to the pronounced crystal mosaicity, a dynamic refinement was not feasible. The unit‐cell parameters were verified by Rietveld refinement from powder X‐ray diffraction data. The crystal structure was validated by many‐body dispersion density functional theory (DFT) calculations. CuPcCl16 crystallizes in the space group C2/m (Z = 2), with the molecules arranged in layers. The structure agrees with that proposed in 1972. [ABSTRACT FROM AUTHOR]

Microcrystal electron diffraction (MicroED) has recently emerged as a promising method for macromolecular structure determination in structural biology. Since the first protein structure was determined in 2013, the method has been evolving rapidly. Several protein structures have been determined and various studies indicate that MicroED is capable of (i) revealing atomic structures with charges, (ii) solving new protein structures by molecular replacement, (iii) visualizing ligand‐binding interactions and (iv) determining membrane‐protein structures from microcrystals embedded in lipidic mesophases. However, further development and optimization is required to make MicroED experiments more accurate and more accessible to the structural biology community. Here, we provide an overview of the current status of the field, and highlight the ongoing development, to provide an indication of where the field may be going in the coming years. We anticipate that MicroED will become a robust method for macromolecular structure determination, complementing existing methods in structural biology. [ABSTRACT FROM AUTHOR]

Dynamical refinement is a well established method for refining crystal structures against 3D electron diffraction (ED) data and its benefits have been discussed in the literature [Palatinus, Petříček & Corrêa, (2015). Acta Cryst. A71, 235-244; Palatinus, Corrêa et al. (2015). Acta Cryst. B71, 740-751]. However, until now, dynamical refinements have only been conducted using the independent atom model (IAM). Recent research has shown that a more accurate description can be achieved by applying the transferable aspherical atom model (TAAM), but this has been limited only to kinematical refinements [Gruza et al. (2020). Acta Cryst. A76, 92-109; Jha et al. (2021). J. Appl. Cryst. 54, 1234-1243]. In this study, we combine dynamical refinement with TAAM for the crystal structure of 1-methyluracil, using data from precession ED. Our results show that this approach improves the residual Fourier electrostatic potential and refinement figures of merit. Furthermore, it leads to systematic changes in the atomic displacement parameters of all atoms and the positions of hydrogen atoms. We found that the refinement results are sensitive to the parameters used in the TAAM modelling process. Though our results show that TAAM offers superior performance compared with IAM in all cases, they also show that TAAM parameters obtained by periodic DFT calculations on the refined structure are superior to the TAAM parameters from the UBDB/MATTS database. It appears that multipolar parameters transferred from the database may not be sufficiently accurate to provide a satisfactory description of all details of the electrostatic potential probed by the 3D ED experiment., (open access.)

Over 30 years ago, it was shown that bonding between atoms has a noticeable effect on convergent beam electron diffraction patterns. The paper by Olech et al. [(2024). IUCrJ, 11, 309-324] demonstrates that its influence is also clearly present in 3D electron diffraction data, opening up new possibilities for quantum crystallography., (open access.)

Structure determination of covalent organic frameworks (COFs) with atomic precision is a bottleneck that hinders the development of COF chemistry. Although three‐dimensional electron diffraction (3D‐ED) data has been used to solve structures of sub‐micrometer‐sized COFs, successful structure solution is not guaranteed as the data resolution is usually low. We demonstrate that the direct‐space strategy for structure solution, implemented using a genetic algorithm (GA), is a successful approach for structure determination of COF‐300 from 3D‐ED data. Structural models with different geometric constraints were considered in the GA calculations, with successful structure solution achieved from room‐temperature 3D‐ED data with a resolution as low as ca. 3.78 Å. The generality of this strategy was further verified for different phases of COF‐300. This study demonstrates a viable strategy for structure solution of COF materials from 3D‐ED data of limited resolution, which may facilitate the discovery of new COF materials in the future. [ABSTRACT FROM AUTHOR]

There is a wealth of materials that are beam sensitive and only exist in nanometric crystals, because the growth of bigger crystals is either impossible or so complicated that it is not reasonable to spend enough time and resources to grow big crystals before knowing their potential for research or applications. This difficulty is encountered in minerals, zeolites, metal-organic frameworks or molecular crystals, including pharmaceuticals and biological crystals. In order to study these crystals a structure determination method for beam sensitive crystals of nanometric size is needed. The nanometric size makes them destined for electron diffraction, since electrons interact much more strongly with matter than X-rays or neutrons. In addition, for the same amount of beam damage, electron diffraction yields more information than X-rays. The recently developed low-dose electron diffraction tomography (LD-EDT) not only combines the advantages inherent in electron diffraction, but is also optimized for minimizing the electron dose used for the data collection. The data quality is high, allowing not only the solution of complex unknown structures, but also their refinement taking into account the dynamical diffraction effects. Here we present several examples of crystals solved and refined by this method. The range of the crystals presented includes two synthetic oxides, Sr5CuGe9O24 and (Na2/3Mn1/3)3Ge5O12, a natural mineral (bulachite), and a metal organic framework (Mn-formiate). The dynamical refinement can be successfully performed on data sets that needed less than 0.1 e−/Å2 for the entire data set.

A DigitalMicrograph script, InsteaDMatic, has been developed to facilitate rapid automated 3D electron diffraction/microcrystal electron diffraction data acquisition by continuous rotation of a crystal with a constant speed, denoted as continuous rotation electron diffraction. The script coordinates microscope functions, such as stage rotation, and camera functions relevant for data collection, and stores the experiment metadata. The script is compatible with any microscope that can be controlled by DigitalMicrograph and has been tested on both JEOL and Thermo Fisher Scientific microscopes. A proof of concept has been performed through employing InsteaDMatic for data collection and structure determination of a ZSM‐5 zeolite. The influence of illumination settings and electron dose rate on the quality of diffraction data, unit‐cell determination and structure solution has been investigated in order to optimize the data acquisition procedure. [ABSTRACT FROM AUTHOR]

A novel crystalline high‐silica zeolite with 12×8‐membered ring (R) channel system is prepared with the aid of the 3D electron diffraction (3D ED) technique. A crystal with the same topology as one of the predicted daughter structures of CIT‐13 germanosilicate, named ECNU‐23 (East China Normal University 23) was coincidentally detected by the 3D ED investigation during the structure characterization of the "pure" powder sample of existing one‐dimension (1D) 10‐R ECNU‐21. By controlling the alkaline‐assisted hydrolysis under moderate conditions, we purified the phase of ECNU‐23 by selectively breaking and removing the chemically weak Ge(Si)‐O‐Ge and metastable Si‐O‐Si bonds. Its structure was determined based on the 3D ED data, and confirmed by high‐resolution TEM images and powder X‐ray diffraction (PXRD) data. The aluminosilicate Al‐ECNU‐23 shows unique catalytic properties in the isomerization/ disproportionation of m‐xylene as solid‐acid catalyst. [ABSTRACT FROM AUTHOR]