X-ray structural, magnetization and Mn single crystal NMR investigations of Mn12O12 (CH2BrCOO)16(4H2O) Æ 4CH2Cl2 indicate that this highly symmetric ðI 4Þ lattice, devoid of hydrogen bonding of the Mn12-framework with the molecules of lattice hydration, might be an improved model for studying single-molecule magnetism. Single crystal NMR yield much enhanced NMR data as compared to magnetically ...

The atomic-scale details during melting of a surface-free Lennard-Jones crystal were monitored using molecular dynamics simulations. Melting occurs when the superheated crystal spontaneously generates a sufficiently large number of spatially correlated destabilized particles that simultaneously satisfy the Lindemann and Born instability criteria. The accumulation and coalescence of these intern...

On the basis of Maxwell's equations and a plane wave expansion method, photonic band structure is computed for 3D chalcogenide photonic crystal with diamond lattice. The geometrical influence on the photonic bandgap is studied for three dimensional chalcogenide photonic crystal of diamond lattice for both chalcogenide spheres in air and air spheres in chalcogenide background. The air spheres in...

In this paper, a photonic crystal waveguide with point defects and lattice constant perturbations of +5%, -5% are being investigated. Firstly waveguide structures with constant and specific parameters are being studied and photonic band gap diagrams for TE/TM modes are depicted; then pulse propagation in the frequencies available in the band gap are shown. After that, effects of parameters like...

In this paper, a Y-shaped power splitter based on a two dimensional photonic crystal (PhC) for TE modes is designed and optimized. A triangular lattice of air holes is used for Y-shaped power divider. For analyzing these structures, plane wave expansion (PWE) and finite difference time domain (FDTD) methods are used. The simulation results show that more than 98% of the input power is transmitt...

A direct observation of the photochemical switching between colloidal crystals with different lattice constants in a liquid-crystal (LC) emulsion is reported. Glycerol droplets introduced in a nematic liquid crystal form two-dimensional hexagonal colloidal crystal at the nematic-air interface with a lattice constant depending on the surface tension sigmaLCA. We dope an azobenzene derivative int...

The inclusion of novel small molecules in crystallization experiments has provided very encouraging results and this method is now emerging as a promising alternative strategy for crystallizing 'problematic' biological macromolecules. These small molecules have the ability to promote lattice formation through stabilizing intermolecular interactions in protein crystals. Here, the use of 1,3,6,8-...

Nanostructured As2Ni3O8 samples were synthesized via facile solid-state reactions at 850 and 950 °C for 8h using As2O3, Ni(CH3COO)2.2H2O and Ni(NO3)2.6H2O raw materials. The synthesized nanomaterials were characterized by powder X-ray diffraction (PXRD) technique and fourier-transform infrared (FTIR) spectroscopy. The rietveld analyses showed that the obtained materials were crystallized well i...

The ability to prepare single-crystal faces has become central to developing and testing models for chemistry at interfaces, spectacularly demonstrated by heterogeneous catalysis and nanoscience. This ability has been hampered for hexagonal ice, Ih--a fundamental hydrogen-bonded surface--due to two characteristics of ice: ice does not readily cleave along a crystal lattice plane and properties ...

Recent challenges in biological X-ray crystallography include the processing of modulated diffraction data. A modulated crystal has lost its three-dimensional translational symmetry but retains long-range order that can be restored by refining a periodic modulation function. The presence of a crystal modulation is indicated by an X-ray diffraction pattern with periodic main reflections flanked ...