A simple synthesis of the zerovalent complex Mo[P(OCH(3))(3)](6) has been devised from a potassium reduction of MoCl(4)(tetrahydrofuran)(2) followed by reaction with trimethyl phosphite at 70 degrees . Protonation of this octahedral complex gave only low yields of the expected seven-coordinate hydride, HMo[P(OCH(3))(3)](6) (+). The major product was an octahedral nonhydridic cation, Mo[P(OCH(3)...

The first alkali metal and magnesium mixed borate fluoride, Li(0.8)Mg(2.1)B2O5F, was prepared by the high-temperature solution method. It crystallizes in the monoclinic space group P2(1)/n (no. 14) with lattice constants a = 3.0881(4) Å, b = 13.6020(2) Å, c = 9.6563(1) Å, β = 91.744(9)°, Z = 4. In the structure, a special magnesium-oxygen-fluorine octahedral chain is found in borates for the fi...

We derive the structural principles of polyhedral allotropes of phosphorus, introducing three distinct families of black phosphorus nanostructures. The predicted tetrahedral, octahedral, and icosahedral phosphorus cages can also be considered as phosphorus fullerenes. Phosphorus cages up to P(888) are systematically investigated by quantum chemical methods, and their thermodynamic stabilities a...

A novel approach to incorporate cobalt atoms into a magnetite single crystal is demonstrated by a combination of x-ray spectro-microscopy, low-energy electron diffraction, and density-functional theory calculations. Co is deposited at room temperature on the reconstructed magnetite (001) surface filling first the subsurface octahedral vacancies and then occupying adatom sites on the surface. Pr...

A comparison is made of two different approaches to the description of phase transitions in the A2BX4 structure (space group D4&, I4/mmm) due to rigid octahedral tiltings. The lower-symmetry subgroups due to coupling of the K»f (X2) and E&2~ (P4) representations (6 tilts) to other tilting modes are listed. All observed transitions in the A2BX4 structure are of the octahedral tilting types. Thes...

Charge densities of iso-structural metal hexaborides, a transparent metal LaB6 and a semiconductor BaB6, have been determined using the d > 0.22 Å ultra-high resolution synchrotron radiation X-ray diffraction data by a multipole refinement and a maximum entropy method (MEM). The quality of the experimental charge densities was evaluated by comparison with theoretical charge densities. The stron...

We determine the phase diagram of a binary mixture of small and large hard spheres with a size ratio of 0.3 using free-energy calculations in Monte Carlo simulations. We find a stable binary fluid phase, a pure face-centered-cubic (fcc) crystal phase of the small spheres, and binary crystal structures with LS and LS(6) stoichiometries. Surprisingly, we demonstrate theoretically and experimental...

We introduce columnar shifts-collective rigid-body translations-as a structural degree of freedom relevant to the phase behaviour of molecular perovskites ABX3 (X = molecular anion). Like the well-known octahedral tilts of conventional perovskites, shifts also preserve the octahedral coordination geometry of the B-site cation in molecular perovskites, and so are predisposed to influencing the l...

Bulk nanostructured materials are made from the assembly of octahedral PbSe nanocrystals. After thermal annealing, the artificial bulk demonstrates a large difference in behavior depending on the temperature, and a large variation of room-temperature resistivity of up to seven orders of magnitude. This variation originates from the high-indexed sharp edges of the octahedral nanocrystals. As the...