A protocol for the ab initio crystal structure determination of powdered solids at natural isotopic abundance by combining solid-state NMR spectroscopy, crystal structure prediction, and DFT chemical shift calculations was evaluated to determine the crystal structures of four small drug molecules: cocaine, flutamide, flufenamic acid, and theophylline. For cocaine, flutamide and flufenamic acid,...

the structure of the nonaaquayttrium (iii) bromate, [y(h2o)9](bro3)3, at low temperature (100 k) has been studied by means of single-crystal x-ray diffraction. crystallography shows a hexagonal unit cell, space group p63/mmc (no. 194) with z = 2, a = b = 11.7104(11) å, c = 6.6259(5) å and v = 786.90(12) å3 at 100 k. the hydrated trivalent yttrium(iii) ion forms a tricapped trigonal prism, in wh...

One of the great challenges of modern science is to faithfully model, and understand, matter at a wide range of scales. Starting with atoms, the vastness of the space of possible configurations poses a formidable challenge to any simulation of complex atomic and molecular systems. We introduce a computational method to reduce the complexity of atomic configuration space by systematically recogn...

The crystal structure of the title Schiff base complex is obtained by single-crystal X-ray diffraction data.The solid state structure determination reveals that the coordination geometry around the copper(II) center istetrahedrally distorted square-planar. The crystal packing shows one dimensional infinite chains which arisesfrom the intermolecular interaction and stabilize the crystal packing.

The dominant factor in determining the atomic structure of grain boundaries is the crystal structure of the material, e.g. FCC vs. BCC. However, for a given crystal structure, the structure of grain boundaries can be influenced by electronic effects, i.e. by the element comprising the crystal. Understanding and modeling the influence of electronic structure on defect structures is a key ingredi...

HAADF imaging is directly interpretable and atomic number (Z) sensitive, allowing researchers to obtain structural and chemical information of the material at the atomic level with sub-Å resolution [1] . For Mo-V-M-Ta (M = Te or Sb) complex oxides catalysts, HAADF has been applied to reveal local cation distribution [2] , structure and chemistry of the crystal defects [3] , polar domain structu...

We demonstrate that a Bose-Einstein condensate in an optical lattice forms a reconfigurable matter-wave structure with a band-gap spectrum, which resembles a nonlinear photonic crystal for light waves. We study in detail the case of a two-dimensional square optical lattice and show that this atomic band-gap structure allows nonlinear localization of atomic Bloch waves in the form of two-dimensi...

The peptide Boc-Val-Phe-OMe 1 bearing sequence similarity with the central hydrophobic cluster (CHC) of Alzheimer's Aβ(18-19) peptide self-assembles to produce amyloid-like straight unbranched fibrils as examined by atomic force microscopy and Congo red assay. Single crystal X-ray diffraction offers the atomic level structure of the supramolecular parallel β-sheet aggregation and antiparallel s...

The crystal structures of the natural and recombinant antiviral lectin scytovirin (SVN) were solved by single-wavelength anomalous scattering and refined with data extending to 1.3 A and 1.0 A resolution, respectively. A molecule of SVN consists of a single chain 95 amino acids long, with an almost perfect sequence repeat that creates two very similar domains (RMS deviation 0.25 A for 40 pairs ...

the crystal structure of the compound c20 h24 n2 o24 was determined by direct methods. thecrystals are monoclinic, space group p21/n, and unit cell parameters are: a= 10.2342 (9), b=4.8763 (5),c=19.3578 (11) a, β =98.9632 (10) o ,v=956.6 (5) a3, z=2, dc=1.239grm-3, dm=1.22grm-3. the final rfactorsare converged to r=0.059 and rw=0.056 for 553 independent observed reflections. themolecules are li...