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Journal articles on the topic 'Crystal structure geometry'

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Published: 4 June 2021

Last updated: 6 February 2022

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1

Eberhart, Mark. "From topology to geometry." Canadian Journal of Chemistry 74, no. 6 (1996): 1229–35. http://dx.doi.org/10.1139/v96-138.

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A systematic study of the charge density topologies corresponding to a number of transition metal aluminides with the B2 structure indicates that unstable crystal structures are sometimes associated with uncharacteristic topologies. This observation invites the speculation that the "distance" to a topological instability might relate to a metals phase behavior. Following this speculation, a metric is imposed on the topological theory of Bader, producing a geometrical theory, where it is now possible to assign a distance from a calculated charge density topology to a topological instability. Fo

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2

Fan, Xiao Hong, Bin Xu, Yong Xu, et al. "Application of Materials Studio Modeling in Crystal Structure." Advanced Materials Research 706-708 (June 2013): 7–10. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.7.

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Modeling of crystal structure in material science curriculum was practiced and applied to keep it simple and understandable by using MS. The unit cells and atomic configurations are produced to show the theory system of geometry description of crystal structure. Many examples, as diamond, graphite, nanomaterial and advanced carbon materials, are employed to describe the main application of MS in material science teaching. According to these atomic modeling configurations, crystal structures exhibit a clearly and understandable appearance for us. So, the meaning of learning and understanding th

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3

Carter, Kay L., Tasneem A. Siddiquee, Kristen L. Murphy, and Dennis W. Bennett. "The surprisingly elusive crystal structure of sodium metabisulfite." Acta Crystallographica Section B Structural Science 60, no. 2 (2004): 155–62. http://dx.doi.org/10.1107/s0108768104003325.

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The crystal structure of Na2S2O5, a simple and common ionic compound, is reported here for the first time. The crystals form non-merohedral twins, with the twin domains related by a twofold axis which bisects the angle between the a and c axes of each unit cell. The structure was determined from a single-crystal fragment of a twinned crystal that had undergone cleavage along the twin boundary. In addition to the problems associated with twinning, space-group determination proved difficult as well, with the structure initially determined in the P21 space group appearing to be disordered with tw

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4

McColm, Greg. "Crystal structure prediction: from topology to geometry." Acta Crystallographica Section A Foundations and Advances 74, a1 (2018): a73. http://dx.doi.org/10.1107/s0108767318099269.

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5

Tannous, C. "Crystal structure, x-ray diffraction and oblique geometry." European Journal of Physics 41, no. 1 (2019): 015501. http://dx.doi.org/10.1088/1361-6404/ab4d65.

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6

Montgomery, Craig D., Steven J. Rettig, and Bryn Shurmer. "Crystal structure of the spirophosphorane (OCMe2C(O)O)2PH." Canadian Journal of Chemistry 76, no. 7 (1998): 1060–63. http://dx.doi.org/10.1139/v98-108.

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The crystal structure of the spirobicyclic phosphorane (OCMe2C(O)O)2PH, 1, has been determined. Crystals of C8H13O6P, 1, are orthorhombic, a = 10.515(2), b = 10.623(2), c = 20.552(2) Å, Z = 8, space group Pca21. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R = 0.037 (Rw = 0.033) for 1616 reflections with I > 3sigma(I). The structure consists of two independent molecules each displaying a distorted trigonal bipyramidal geometry; the distortion follows closely the Berry pseudorotation coordinate.Key words: crystal structure, phosphorane, Be

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7

Atria, Ana María, Maria Teresa Garland, and Ricardo Baggio. "Crystal structure of 4,4′-(disulfanediyl)dibutanoic acid–4,4′-bipyridine (1/1)." Acta Crystallographica Section E Structure Reports Online 70, no. 9 (2014): 157–60. http://dx.doi.org/10.1107/s1600536814018558.

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4,4′-(Disulfanediyl)dibutanoic acid (dtba) and 4,4′-bipyridine (4,4′-bpy) crystallize in an 1:1 ratio, leading to the title co-crystal with composition C8H14O4S2·C10H8N2. A distinctive feature of the crystal structure is the geometry of the dtba moiety, which appears to be stretched [with a 9.98 (1) Å span between outermost carbons] and acts as an hydrogen-bonding connector, forming linear chains along [-211] with the 4,4′-bpy moiety by way of O—H...N hydrogen bonds and C—H...O interactions. The influence of the molecular shape on the hydrogen-bonding pattern is analysed by comparing the title

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8

Knauer, Lena, Christopher Golz, Ulrike Kroesen, Stephan G. Koller, and Carsten Strohmann. "Crystal structure of dibenzyldimethylsilane." Acta Crystallographica Section E Crystallographic Communications 71, no. 6 (2015): o391—o392. http://dx.doi.org/10.1107/s2056989015008713.

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In the title compound, C16H20Si, a geometry different from an ideal tetrahedron can be observed at the Si atom. The bonds from Si to the benzylic C atoms [Si—C = 1.884 (1) and 1.883 (1) Å] are slightly elongated compared to the Si—Cmethylbonds [Si—C = 1.856 (1) and 1.853 (1) Å]. The Cbenzyl—Si—Cbenzylbond angle [C—Si—C = 107.60 (6)°] is decreased from the ideal tetrahedral angle by 1.9°. These distortions can be explained easily by Bent's rule. In the crystal, molecules interact only by van der Waals forces.

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9

Agbeworvi, George, Zerihun Assefa, Richard E. Sykora, and Jared D. Taylor. "Crystal structure oftert-butyldiphenylphosphine oxide." Acta Crystallographica Section E Crystallographic Communications 71, no. 6 (2015): o400. http://dx.doi.org/10.1107/s2056989015008919.

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In the structure of the title triorganophosphine oxide, C16H19OP, the P—O bond is 1.490 (1) Å. The P atom has a distorted tetrahedral geometry. The O atom interacts with both phenyl groups of a neighboring molecule [C...O = 2.930 (3) and 2.928 (4) Å]. The C—O interaction directs an extended supramolecular arrangement along thea-axis.

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10

Willner, H., S. J. Rettig, J. Trotter, and F. Aubke. "The crystal and molecular structure of gold tris(fluorosulfate)." Canadian Journal of Chemistry 69, no. 3 (1991): 391–96. http://dx.doi.org/10.1139/v91-060.

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Single crystals of gold(III) tris(fluorosulfate) are obtained by recrystallization from bis(fluorosulfuryl) peroxide, S2O6F2, under O2 pressure. The crystals of [Au(SO3F)3]2 are monoclinic, a = 9.700(4), b = 9.222(2), c = 10.810(4)Å, β = 94.43(3)°, Z = 2, space group P21/a. The structure was solved by heavy atom methods and was refined by full-matrix least-squares procedures, R(F) = 0.038 and Rw(F) = 0.050 for 1491 reflections with I ≥ 3σ(I). The structure consists of centrosymmetric [Au(SO3F)3]2 dimers containing two bidentate, symmetrically bridging and four monodentate, terminal SO3F ligand

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11

Klunnikova, Yu V., S. P. Malyukov, A. V. Filimonov, and N. Zhang. "Analysis of heat transfer processes for sapphire growth by horizontal directed crystallization method." Journal of Advanced Dielectrics 10, no. 01n02 (2020): 2060001. http://dx.doi.org/10.1142/s2010135x20600012.

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This research summarizes the analytical and experimental results of heat-transfer processes influence on defects formation during sapphire crystal growth by horizontal directed crystallization method (HDC). The shape of solid-melt interface significantly influences the process of sapphire crystals growth by this method. We receive the Stefan problem solution for sapphire crystals growth. It allows investigating the crystal growth process and the related factors (thermal stresses on different stages of growth process), their influence on defects formation. We investigate the main reasons for th

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12

Trzesowski, Andrzej. "Geometry of crystal structure with defects. I. Euclidean picture." International Journal of Theoretical Physics 26, no. 4 (1987): 311–33. http://dx.doi.org/10.1007/bf00672242.

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13

Brewster, Aaron S., David G. Waterman, James M. Parkhurst, et al. "Improving signal strength in serial crystallography with DIALS geometry refinement." Acta Crystallographica Section D Structural Biology 74, no. 9 (2018): 877–94. http://dx.doi.org/10.1107/s2059798318009191.

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The DIALS diffraction-modeling software package has been applied to serial crystallography data. Diffraction modeling is an exercise in determining the experimental parameters, such as incident beam wavelength, crystal unit cell and orientation, and detector geometry, that are most consistent with the observed positions of Bragg spots. These parameters can be refined by nonlinear least-squares fitting. In previous work, it has been challenging to refine both the positions of the sensors (metrology) on multipanel imaging detectors such as the CSPAD and the orientations of all of the crystals st

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14

Akiyama, Tomonori, Yusuke Yamada, Naoki Takaya, Shinsaku Ito, Yasuyuki Sasaki, and Shunsuke Yajima. "Crystal structure of an IclR homologue fromMicrobacteriumsp. strain HM58-2." Acta Crystallographica Section F Structural Biology Communications 73, no. 1 (2017): 16–23. http://dx.doi.org/10.1107/s2053230x16019208.

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The bacterial transcription factor IclR (isocitrate lyase regulator) is a member of a one-component signal transduction system, which shares the common motif of a helix–turn–helix (HTH)-type DNA-binding domain (DBD) connected to a substrate-binding domain (SBD). Here, the crystal structure of an IclR homologue (Mi-IclR) fromMicrobacteriumsp. strain HM58-2, which catabolizes acylhydrazide as the sole carbon source, is reported. Mi-IclR is expected to regulate an operon responsible for acylhydrazide degradation as an initial step. Native single-wavelength anomalous diffraction (SAD) experiments

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15

Graiff, Claudia, Daniele Pontiroli, Laura Bergamonti, Chiara Cavallari, Pier Paolo Lottici, and Giovanni Predieri. "Structural investigation ofN,N′-methylenebisacrylamideviaX-ray diffraction assisted by crystal structure prediction." Journal of Applied Crystallography 48, no. 2 (2015): 550–57. http://dx.doi.org/10.1107/s1600576715004161.

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The crystal structure ofN,N′-methylenebisacrylamide was determined through the geometry optimization of the molecular unit with density functional theory and conformational analysis, and then through the calculation of the packingviaa crystal structure prediction protocol, based on lattice energy minimization. All the calculated structures were ranked, comparing their powder pattern with the laboratory low-quality X-ray diffraction data. Rietveld refinement of the best three proposed structures allowed the most probable crystal arrangement of the molecules to be obtained. This approach was ess

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16

Obata, Shigeaki, Mitsuaki Sato, and Hitoshi Goto. "Theoretical Prediction of Crystal Polymorphs for Organic Molecules." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1626. http://dx.doi.org/10.1107/s2053273314083739.

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Crystal structure prediction is one of the useful theoretical tools for designing and synthesizing new materials in pharmaceutical therapeutics and industrial electronics. Furthermore, the prediction can provide immense valuable scientific knowledge on a crystal growth, polymorphism and many properties of organic molecular crystals. Therefore, we have started the development of high-speed and high-accurate prediction method for organic molecular crystal structures [1,2]. In this work, we demonstrate the theoretical predictions of crystal structures of fourteen target molecules that were used i

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17

Matsushita, Yoshitaka, and Mercouri G. Kanatzidis. "Synthesis and Structure of Li4GeS4a." Zeitschrift für Naturforschung B 53, no. 1 (1998): 23–30. http://dx.doi.org/10.1515/znb-1998-0107.

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The compound Li4GeS4 has been prepared as transparent, light yellow moisture-sensitive crystals. Li4GeS4 belongs to the space group Pnma with a = 14.107(6) Å, b = 7.770(3) Å and c = 6.162(2) Å. The crystal structure was solved by direct-methods. The final R and Rw-values are 1.85 and 1.65% for 866 observed reflections. The Li4GeS4 structure has three crystallographically independent lithium sites and one germanium site. The lithium atoms adopt two different coordination types. The Li l atom is coordinated to five sulfur atoms in a square pyramidal geometry, while the Li2 and Li3 atoms have dis

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18

Martínez de León, Carla, Hugo Tlahuext, and Jean-Michel Grévy. "Crystal structure of 2,5-bis(diphenylphosphanyl)furan." Acta Crystallographica Section E Crystallographic Communications 71, no. 12 (2015): o922—o923. http://dx.doi.org/10.1107/s2056989015020964.

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In the title compound, C28H22OP2, each of the P atoms has an almost perfect pyramidal geometry, with C—P—C angles varying from 100.63 (10) to 102.65 (9)°. In the crystal, neighbouring molecules are linkedviaweak C—H...π interactions, forming supramolecular chains along theb-axis direction.

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19

Merola, Joseph S., та Arthur W. Grieb. "Crystal structure of chlorido(η2-phenyl isothiocyanate-κ2C,S)-mer-tris(trimethylphosphane-κP)iridium(I)". Acta Crystallographica Section E Structure Reports Online 70, № 11 (2014): 352–54. http://dx.doi.org/10.1107/s160053681402162x.

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The molecule of the title compound, [IrCl(C7H5NS)(C3H9P)3], is a distorted octahedral iridium complex with three PMe3ligands arranged in a meridional geometry, a chloride ioncisto all three PMe3groups and the phenyl isothiocyanate ligand bonded in an η2-fashion through the C and S atoms. The C atom istransto the chloride ion and the S atom is responsible for a significant deviation from an ideal octahedral geometry. The geometric parameters for the metal-complexing phenyl isothiocyanate group are compared with other metal-complexed phenyl isothiocyanates, as well as with examples of uncomplexe

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20

Hillman, Zachary E., Joseph M. Tanski, and Andrea Roberts. "Crystal and geometry-optimized structure of an anthracene-based Diels–Alder adduct." Acta Crystallographica Section C Structural Chemistry 76, no. 7 (2020): 639–46. http://dx.doi.org/10.1107/s2053229620008128.

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Computational calculations of an anthracene-based Diels–Alder adduct, namely, 17-ethyl-1-hydroxymethyl-17-azapentacyclo[6.6.5.02,7.09,14.015,19]nonadeca-2,4,6,9,11,13-hexaene-16,18-dione, C21H19NO3, predicting density functional theory (DFT) optimized geometries in the gas phase are compared in terms of accuracy relative to the solid-state crystal structure and computational cost. Crystal structure determination and Hirshfeld surface analysis of the racemic product reveal that the molecules are linked by O—H...O=C hydrogen bonds between the hydroxy and carbonyl groups, accounting for 9.5% of t

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21

Knopf, Kevin M., Guy Crundwell, and Barry L. Westcott. "Crystal structure of hexaaquadichloridoytterbium(III) chloride." Acta Crystallographica Section E Crystallographic Communications 71, no. 6 (2015): i5. http://dx.doi.org/10.1107/s2056989015008488.

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The crystal structure of the title compound, [YbCl2(H2O)6]Cl, was determined at 110 K. Samples were obtained from evaporated acetonitrile solutions containing the title compound, which consists of a [YbCl2(H2O)6]+cation and a Cl−anion. The cations in the title compound sit on a twofold axis and form O—H...Cl hydrogen bonds with the nearby Cl−anion. The coordination geometry around the metal centre forms a distorted square antiprism. The ytterbium complex is isotypic with the europium complex [Tambrorninoet al.(2014).Acta Cryst.E70, i27].

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22

Ammon, H. L., Z. Du, R. D. Gilardi, P. R. Dave, F. Forohar, and T. Axenrod. "Structure of 1,3,5,7-tetranitro-3,7-diazabicyclo-[3.3.0]octane. Structure solution from molecular packing analysis." Acta Crystallographica Section B Structural Science 52, no. 2 (1996): 352–56. http://dx.doi.org/10.1107/s0108768195010652.

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The structure was solved with the molecular packing program MOLPAK, starting with a molecular mechanics-geometry optimized model of an isolated molecule. The best predicted crystal structures from the MOLPAK procedure were subjected to lattice energy refinement with the WMIN program. The MOLPAK/WMIN-predicted crystal structure, whose cell parameters were closest to the experimental values, gave an initial R of 0.48 for the 173 data to 0 = 25°. Four cycles of least-squares refinement of x, y, z and U gave an R of 0.27 for the 277 data to 0 = 30°. Final R = 0.038, wR = 0.044. There are no unusua

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23

Norby, P. "Synchrotron Powder Diffraction using Imaging Plates: Crystal Structure Determination and Rietveld Refinement." Journal of Applied Crystallography 30, no. 1 (1997): 21–30. http://dx.doi.org/10.1107/s0021889896009995.

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The combination of intense X-ray synchrotron radiation and an imaging-plate area detector makes it possible to extract real-time structural information using Rietveld refinement of individual time slices. Powder diffraction data from capillary samples were collected using a flat imaging plate mounted perpendicular to, or at an oblique angle to, the incoming beam. Owing to the geometry of the experiments, several factors must be taken into account when Rietveld refinement of powder diffraction data obtained using a flat imaging plate is performed: (i) nonequal step sizes are obtained when the d

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24

Becker, H., BW Skelton, and AH White. "Molecular Geometry of 1,2-Bis(9-anthryl)acetylene." Australian Journal of Chemistry 38, no. 10 (1985): 1567. http://dx.doi.org/10.1071/ch9851567.

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The structure of 1,2-bis(9-anthryl)acetylene has been determined by single-crystal X-ray diffraction, being refined by least squares to a residual of 0.050 for 566 independent 'observed' reflections. Crystals are monoclinic, P21/c, a 12.432(5), b 5.112(1), c 18.758(8) Ǻ, β 126.58(2)°, Z 2. The molecule is centrosymmetric , with the two anthracene moieties coplanar. The spatial separation between H1/H8 and their centrosymmetric equivalents is 2.1 Ǻ. The length of the acetylenic bond is 1.193(10) Ǻ.

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25

Naberezhnov, A. A., A. E. Sovestnov, and A. V. Fokin. "Crystal structure of indium and lead under confined geometry conditions." Technical Physics 56, no. 5 (2011): 637–41. http://dx.doi.org/10.1134/s1063784211050240.

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26

Brucker, Eric Allen, John S. Olson, Masao Ikeda-Saito, and George N. Phillips. "Nitric oxide myoglobin: Crystal structure and analysis of ligand geometry." Proteins: Structure, Function, and Genetics 30, no. 4 (1998): 352–56. http://dx.doi.org/10.1002/(sici)1097-0134(19980301)30:4<352::aid-prot2>3.0.co;2-l.

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27

Hyde, S. T., and Sten Andersson. "Differential geometry of crystal structure descriptions, relationships and phase transformation." Zeitschrift für Kristallographie 170, no. 1-4 (1985): 225–39. http://dx.doi.org/10.1524/zkri.1985.170.1-4.225.

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28

Główka, Marek L., Andrzej Olczak, Wincenty Kwapiszewski, and Włodzimierz Białasiewicz. "Geometry of lidocaine-like molecules. 1. Crystal structure of tocainide." Journal of Chemical Crystallography 26, no. 7 (1996): 515–18. http://dx.doi.org/10.1007/bf01668314.

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Trzesowski, Andrzej. "Geometry of crystal structure with defects. II. Non-Euclidean picture." International Journal of Theoretical Physics 26, no. 4 (1987): 335–55. http://dx.doi.org/10.1007/bf00672243.

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Wu, Hui, Michael R. Hartman, Terrence J. Udovic, et al. "Structure of the novel ternary hydrides Li4 Tt 2D (Tt = Si and Ge)." Acta Crystallographica Section B Structural Science 63, no. 1 (2007): 63–68. http://dx.doi.org/10.1107/s0108768106046465.

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The crystal structures of newly discovered Li4Ge2D and Li4Si2D ternary phases were solved by direct methods using neutron powder diffraction data. Both structures can be described using a Cmmm orthorhombic cell with all hydrogen atoms occupying Li6-octahedral interstices. The overall crystal structure and the geometry of these interstices are compared with those of other related phases, and the stabilization of this novel class of ternary hydrides is discussed.

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Bortel, Gabor, Miklos Tegze, and Gyula Faigel. "Structure factors from pseudo-Kossel line patterns." Journal of Applied Crystallography 38, no. 5 (2005): 780–86. http://dx.doi.org/10.1107/s0021889805024660.

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Pseudo-Kossel lines are cones of Bragg reflections that contain information on the structure of single crystals. Nevertheless, they are not used in structure determination. The feasibility of obtaining a data set of structure factor amplitudes from a pseudo-Kossel line pattern measurement is presented in this paper. The experimental setup shown allows the detection of almost the complete cone pattern around the sample. The measurement process is significantly simpler than data collection with a conventional four-circle diffractometer. The extraction of structural information from the measured

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Gorelik, Tatiana E., Stefan Habermehl, Aleksandr A. Shubin, et al. "Crystal structure of copper perchlorophthalocyanine analysed by 3D electron diffraction." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 77, no. 4 (2021): 662–75. http://dx.doi.org/10.1107/s2052520621006806.

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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 stati

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Kim, Deok Soo, Yong Chae Chung, Sang Won Seo, Sang Pil Kim, and Chong Min Kim. "Extraction of Crystal Structures Based on Euclidean Voronoi Diagram and Angle Distributions among Atoms." Key Engineering Materials 317-318 (August 2006): 881–84. http://dx.doi.org/10.4028/www.scientific.net/kem.317-318.881.

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The structural configurations of atom constituting materials are one of the fundamental factors in the study of physical properties of materials. Presented in this paper is a mathematical and computational methodology to efficiently classify a given atomic structure of an arbitrary material into groups of atoms in BCC, FCC, and HCP crystal structures. The approach is based on the angle distributions among neighboring atoms efficiently identified by a computational geometry technique called Voronoi diagram. In this paper, the presented mathematical theory was applied to analyze a multi-layer at

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Gao, Nansha, Jiu Hui Wu, and Dong Guan. "Research on the large band gaps in multilayer radial phononic crystal structure." Modern Physics Letters B 30, no. 10 (2016): 1650108. http://dx.doi.org/10.1142/s0217984916501098.

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In this paper, we study the band gaps (BGs) of new proposed radial phononic crystal (RPC) structure composed of multilayer sections. The band structure, transmission spectra and eigenmode displacement fields of the multilayer RPC are calculated by using finite element method (FEM). Due to the vibration coupling effects between thin circular plate and intermediate mass, the RPC structure can exhibit large BGs, which can be effectively shifted by changing the different geometry values. This study shows that multilayer RPC can unfold larger and lower BGs than traditional phononic crystals (PCs) a

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Gray, Jessica L., Deidra L. Gerlach та Elizabeth T. Papish. "Crystal structure of (perchlorato-κO)(1,4,7,10-tetraazacyclododecane-κ4N)copper(II) perchlorate". Acta Crystallographica Section E Crystallographic Communications 73, № 1 (2017): 31–34. http://dx.doi.org/10.1107/s2056989016019563.

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The crystal structure of the title salt, [Cu(ClO4)(C8H20N4)]ClO4, is reported. The CuIIion exhibits a square-pyramidal geometry and is coordinated by the four N atoms of the neutral 1,4,7,10-tetraazacyclododecane (cyclen) ligand and an O atom from one perchlorate anion, with the second perchlorate ion hydrogen-bonded to one of the amine N atoms of the cyclen ligand. Additional N—H...O hydrogen bonds between the amine H atoms and the coordinating and non-coordinating perchlorate groups create a three-dimensional network structure. Crystals were grown from a concentrated methanol solution at amb

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Sarr, Modou, Aminata Diasse-Sarr, Libasse Diop, Laurent Plasseraud, and Hélène Cattey. "Crystal structure of bis(cyclohexylammonium) diphenyldioxalatostannate(IV)." Acta Crystallographica Section E Crystallographic Communications 71, no. 2 (2015): 151–53. http://dx.doi.org/10.1107/s2056989014027716.

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Reaction of oxalic acid and diphenyltin dichloride in the presence of cyclohexylamine led to the formation of the title salt, (C6H14N)2[Sn(C6H5)2(C2O4)2]. The dianion is made up from an Sn(C6H5)2moietycis-coordinated by two chelating oxalate anions, leading to an overall distorted octahedral coordination geometry of the SnIVatom. The negative charges are compensated by two surrounding cyclohexylammonium cations adopting chair conformations each. In the crystal, anions and cations are linkedviaa network of N—H...O hydrogen bonds into a layered arrangement parallel to (101).

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Angermaier, Klaus, and Hubert Schmidbaur. "Preparation and Structure of Poly(gold)telluronium Salts." Zeitschrift für Naturforschung B 51, no. 6 (1996): 879–82. http://dx.doi.org/10.1515/znb-1996-0619.

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Abstract Tris[(triphenylphosphine)gold(I)]telluronium tetrafluoroborate (1) was prepared from the corresponding oxonium salt and bis(t-butyldimethylsilyl)tellurium in dichloromethane at -78°C. The product forms yellow crystals, thermally stable to 125°C. It was identified by standard analytical and spectroscopic techniques, including a single crystal X-ray diffraction study. In the crystal lattice, the cations form tellurium-capped triangles of gold, which are associated into dimers through short intermolecular Au -Au contacts, resembling those in the corresponding sulfur and selenium compound

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Groom, Colin, Suzanna Ward, Neil Feeder, Elna Pidcock, Peter Wood, and Peter Galek. "Using the Knowledge from Every Organic Crystal Structure Ever Published." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C495. http://dx.doi.org/10.1107/s2053273314095047.

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The crystallographic community has done something remarkable and almost unique in science. It has operated in such a way that the data generated in virtually every experiment reported in a publication is available to all. This data, in the form of individual crystal structures, is valuable not just in itself, but as a collection. To fully exploit the results of a new structure determination, we never analyse a single structure, we analyse it in the context of every previous crystal structure. Our knowledge of molecular geometry and molecular interactions derived from these structural databases

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Saliu, Kuburat O., Josef Takats та Robert McDonald. "Crystal structure of tribenzylbis(tetrahydrofuran-κO)lutetium(III)". Acta Crystallographica Section E Crystallographic Communications 74, № 2 (2018): 88–90. http://dx.doi.org/10.1107/s2056989017018254.

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In the title compound, [Lu(C7H7)3(C4H8O)2] (1), the Lu ion is coordinated by three benzyl and two tetrahydrofuran ligands. Two of the benzyl groups are bonded in a classical η1-fashion through the methylene via the ipso-carbon atom of the benzyl ligand in addition to bonding through the methylene C atom, resulting in a modified trigonal–bipyramidal coordination geometry about the Lu center.

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40

Valík, Martin, Pavel Matějka, Eberhardt Herdtweck, Vladimír Král, and Bohumil Dolensky. "A New Bis-Tröger's Base: Synthesis, Spectroscopy, Crystal Structure and Isomerization." Collection of Czechoslovak Chemical Communications 71, no. 9 (2006): 1278–302. http://dx.doi.org/10.1135/cccc20061278.

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A new bis-Tröger's base was prepared from a tetraamine precursor as a mixture of two diastereoisomers. One of the isomers has a chair-like geometry, and the other possesses a boat-like geometry, embodying molecular tweezers. A one-pot preparation of bis-TB isomers and their interconversion under acid conditions was also studied. Structures of both isomers were confirmed by single-crystal X-ray diffraction. Extensive spectroscopic data, including 1H and 13C NMR, IR and Raman spectra of the isomers, are given.

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41

Frampton, Christopher S., James I. Murray, and Alan C. Spivey. "Crystal structure of 1-methylimidazole 3-oxide monohydrate." Acta Crystallographica Section E Crystallographic Communications 73, no. 3 (2017): 372–74. http://dx.doi.org/10.1107/s2056989017002079.

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1-Methylimidazole 3-N-oxide (NMI-O) crystallizes as a monohydrate, C4H6N2O·H2O, in the monoclinic space groupP21withZ′ = 2 (moleculesAandB). The imidazole rings display a planar geometry (r.m.s. deviations = 0.0008 and 0.0002 Å) and are linked in the crystal structure into infinite zigzag strands of ...NMI-O(A)...OH2...NMI-O(B)...OH2... units by O—H...O hydrogen bonds. These chains propagate along theb-axis direction of the unit cell.

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Demakov, Sergey, Iana Kylosova, Stepan Stepanov, and Matthias Bönisch. "A general model for the crystal structure of orthorhombic martensite in Ti alloys." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 77, no. 5 (2021): 749–62. http://dx.doi.org/10.1107/s2052520621007976.

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The present work develops a novel unified approach to describe the crystal structure of orthorhombic martensite (α′′) in Ti alloys independent of chemical composition. By employing a straightforward yet highly instructive solid sphere model for the basic tetrahedral structural unit the crystal structures involved in the β ↔ α′′/α′ martensitic transformation are categorized into several intermediate configurations. Importantly, a new metric is introduced, δ, which unambiguously characterizes the atomic positions inside the orthorhombic unit cell depending on unit-cell geometry. Furthermore, the

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43

Tiekink, ERT, and G. Winter. "The Crystal-Structure of Bis(O-Ethylxanthato)-Triphenylphosphinenickel(II) - Ni(S2COC2H5)2P(C6H5)3." Australian Journal of Chemistry 39, no. 5 (1986): 813. http://dx.doi.org/10.1071/ch9860813.

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The crystal and molecular structure of the 1:1 adduct formed between bis (O- ethylxanthato )nickel(II) and triphenylphosphine is reported. The nickel atom is five-coordinate in a distorted square-pyramidal geometry with a sulfur atom, from an asymmetrically coordinating xanthate ligand , in the apical position. Crystals are triclinic, space group Pī, a 10.265(4), b 14.718(5), c 8.818(4) Ǻ, α 100.77(3), β 92.16(4), γ 89.56(3)° with Z 2. The structure was refined by a least-squares method; R 0.068 for 3301 reflections with I ≥ 3.0σ(I).

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Fleck, Michel, and Ladislav Bohatý. "Syntheses, Crystal Structures and an Overview of Alkali Metal Maleates." Zeitschrift für Naturforschung B 64, no. 5 (2009): 517–24. http://dx.doi.org/10.1515/znb-2009-0507.

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The crystal structures of four alkali salts of maleic acid have been determined by single crystal X-ray diffraction: crystals of rubidium hydrogen maleate, RbH(C4H2O4), are very nearly centrosymmetrical, i. e., only one hydrogen atom position in the crystal structure violates the centrosymmetry. Thus, the space group is Pbc21 rather than Pbcm. The compound is isotypic with potassium hydrogen maleate, KH(C4H2O4), which has previously been described in space group Pbcm. It has been reinvestigated to prove that the correct space group is also Pbc21. The isotypic pair of rubidium hydrogen maleate

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Waterman, Rory, and Gregory L. Hillhouse. "Synthesis and structure of a terminal dinitrogen complex of nickel." Canadian Journal of Chemistry 83, no. 4 (2005): 328–31. http://dx.doi.org/10.1139/v05-011.

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Reaction of petroleum ether solutions of [(dtbpe)Ni]2(η2,µ-C6H6) (1, dtbpe = 1,2-bis(di-tert-butylphosphino)ethane) with triphenylphosphine under a dinitrogen atmosphere gives the Ni(0) dinitrogen adduct (dtbpe)Ni(N2)(PPh3) (2), which can be isolated as dark red crystals in 87% yield. The X-ray crystal structure of 2 reveals pseudotetrahedral geometry about Ni and a terminal dinitrogen ligand with NiN(1) = 1.830(2) Å, N(1)N(2) = 1.112(2) Å, and Ni-N(1)-N(2) = 177.5(2)°. Key words: dinitrogen, nickel, X-ray.

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Nyburg, S. C., and C. H. Faerman. "A crystal structure survey of the geometry of the methoxyphenyl group." Journal of Molecular Structure 140, no. 3-4 (1986): 347–52. http://dx.doi.org/10.1016/0022-2860(86)87017-x.

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Mondal, Biplab, Goutam Kumar Lahiri, Panče Naumov, and Seik Weng Ng. "Crystal structure and geometry-optimization study of 2-benzyliminiomethylene-4-nitrophenolate." Journal of Molecular Structure 613, no. 1-3 (2002): 131–35. http://dx.doi.org/10.1016/s0022-2860(02)00132-1.

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Tai, Xi Shi. "Preparation and X-Ray Crystal Structure of Layered Ca(II) Complex Material." Advanced Materials Research 282-283 (July 2011): 108–11. http://dx.doi.org/10.4028/www.scientific.net/amr.282-283.108.

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A novel Ca(II) complex material was prepared by reaction of O-nitrobenzaldehyde- 3-amino-benzenesulfonic acid with Ca(ClO4)2, and characterized by X-ray single crystal diffraction method. The analytical results shows that the Ca(II) complex was crystallized in the monoclinic system, space group P2(1)/c, with a = 17.515(10) Å, b = 7.019(4) Å, c = 13.853(8) Å, β = 104.855(10) º, V = 1646.3(17) Å3, Z = 2. The geometry of Ca(II) is a slightly distorted dodecahedrall geometry. In the crystal packing, the complex molecules form layered structure by the π-π packing interaction, and the molecules form

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Kurzydłowski, Dominik, Taisiia Chumak, and Jakub Rogoża. "Phase Stability of Chloroform and Dichloromethane at High Pressure." Crystals 10, no. 10 (2020): 920. http://dx.doi.org/10.3390/cryst10100920.

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Chloroform (CHCl3) and dichloromethane (CH2Cl2) are model systems for the study of intermolecular interactions, such as hydrogen bonds and halogen–halogen interactions. Here we report a joint computational (density-functional perturbation theory (DFPT) modelling) and experimental (Raman scattering) study on the behaviour of the crystals of these compounds up to a pressure of 32 GPa. Comparing the experimental information on the Raman band positions and intensities with the results of calculations enabled us to characterize the pressure-induced evolution of the crystal structure of both compoun

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Wang, Alian, Jingyi Han, Lihe Guo, Jianyuan Yu, and Pei Zeng. "Database of Standard Raman Spectra of Minerals and Related Inorganic Crystals." Applied Spectroscopy 48, no. 8 (1994): 959–68. http://dx.doi.org/10.1366/0003702944029640.

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Establishing a standard Raman spectral database for minerals and related inorganic crystals is a very important basis for further increasing the applications of Raman spectroscopy in the geosciences. However, the Raman spectral pattern of a crystal is a function not only of its composition and structure but also of the scattering geometry during the measurement. Therefore, the standard Raman spectrum of a crystal must be measured under well-defined standard conditions. It would be of great interest to establish a standard measuring configuration with which the characteristic Raman spectra of a

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