A tetrahedral curve is an unmixed, usually non-reduced, one-dimensional subscheme of projective 3-space whose homogeneous ideal is the intersection of powers of the ideals of the six coordinate lines. The second and third authors have shown that these curves have very nice combinatorial properties, and they have made a careful study of the even liaison classes of these curves. We build on this ...

The results of a molecular dynamics simulation of a 1.1 molal aqueous MgCl2 solution are compared with newly performed x-ray measurements. The structural properties of the solution are evaluated from the scattering data by a model fit to the experimental structure function. The comparison on the basis of fit parameters and partial structure functions shows an overall good agreement between expe...

In this article we consider the problem of finding Hamiltonian cycles on a tetrahedral mesh. A Hamiltonian cycle is a closed loop through a tetrahedral mesh that visits each tetrahedron exactly once. Using techniques of a novel discrete differential geometry of n-simplices, we could immediately obtain Hamiltonian cycles on a rhombic dodecahedronshaped tetrahedral mesh consisting of 24 tetrahedr...

Abstract Using density-functional theory based simulations, we study how initially disconnected zinc phosphate molecules respond to different externally imposed deformations. Hybridization changes are observed in all cases, which the coordination of atoms irreversibly from tetrahedral seesaw and square pyramidal, whereby system stiffens substantially. The point at stiff networks formed does not...

Metal nanoclusters have recently attracted extensive interest not only for fundamental scientific research, but also for practical applications. For fundamental scientific research, it is of major importance to explore the internal structure and crystallographic arrangement. Herein, we synthesize a gold nanocluster whose composition is determined to be Au60S6(SCH2Ph)36 by using electrospray ion...

Low stacking fault energy face centered cubic (FCC) materials contain characteristic defect structures. Stacking fault tetrahedral are one of those rare structures that occur under special experimental conditions. For the first time, stacking fault tetrahedral were observed in Fe-30Mn-3Al-3Si twinning induced plasticity (TWIP) steel. Their presence resulted from a quenching heat treatment.

A double-walled tetrahedral metal-organic cage assembled in solution from silver(I), 2-formyl-1,8-naphthyridine, halide, and a threefold-symmetric triamine. The AgI4X clusters at its vertices each bring together six naphthyridine-imine moieties, leading to structure which eight tritopic ligands bridge four an (AgI4X)4L8 arrangement. Four form inner set of tetrahedron walls that are surrounded b...

Catalysis by the serine proteinases proceeds via a tetrahedral intermediate whose oxyanion is stabilized by hydrogen-bonding in the oxyanion hole. There have been extensive 13C-NMR studies of oxyanion and tetrahedral intermediate stabilization in trypsin, subtilisin and chymotrypsin using substrate-derived chloromethane inhibitors. One of the limitations of these inhibitors is that they irrever...

We have employed vibrational sum frequency generation (VSFG) to investigate the structure of water at neat oil/water and air/water interfaces through the OH stretching modes of the interfacial water molecules. We find that at the oil/water interface the prevailing structure of the water molecules is a tetrahedral arrangement much like the structure of ice while at the air/water interface we obs...

Emergent superconductivity is strongly correlated with the symmetry of local atomic configuration in parent compounds iron-based superconductors. While chemical doping or hydrostatic pressure can change geometry, these conventional approaches do not provide a clear pathway tuning detailed arrangement predictably, due to complicated structural deformation presence tetragonal-to-orthorhombic phas...