Results of a theoretical study on the properties of Ir4 clusters in the gas–phase and on oxide surfaces are presented. The work is based on density functional theory (DFT) within the generalized gradient approximation (GGA) and ultrasoft pseudopotentials. Properties of a small particle such as Ir4 cluster are entirely determined by its geometry. The already known result that the most stable for...

In this paper we present a new series of 3-dimensional integrable lattice models with N colors. The case N = 2 generalizes the elliptic model of paper [8]. The weight functions of the models satisfy modified tetrahedron equations with N states and give a commuting family of two-layer transfer-matrices. The dependence on the spectral parameters corresponds to the static limit of the modified tet...

Tetrasiladigermatricyclohexanes in two isomeric forms (chair and doubly-bridged tetrahedron) are obtained by the reaction of MeLi with an α-chlorosilyl functionalized NHC-stabilized silagermenylidene. (29)Si NMR at low temperature proves the initial formation of a monomeric NHC-adduct of a disilenyl germylene followed by cyclisation to the isomeric heavy cyclopropene. Addition of an excess of N...

An empirical formula is suggested to describe the mutuaJ dependence of the length of the bonds formed by a central atom in systems built up from equivalent carbon atoms, e.g. diamond, graphite, the cumulene and polyyne chains and intermediate structures between them. A geometrical representation of the relationship is a regular tetrahedron. A point of this tetrahedron characterizes the arrangem...

Modifications in recorder standardization are required to correct inherent scalar differences among potential differences measured in a given electrocardiographic reference frame. In the frontal plane, agreement between the resultant vectors calculated from unipolar limb lead measurements and from standard lead measurements can be obtained by standardizing the galvanometer for recording the uni...

The anatomic apices of a tetrahedron were located on the image surface of living man by reciprocal stimulation of an electrode placed in the esophagus at the assumed electric center of the heart. The rectilineal components of the three-dimensional electrode were not oriented with respect to the axes of the body. Therefore, it was possible to determine the shape of the image tetrahedron but not ...

We introduce a linear algebraic object called bidiagonal triad. A triad consists of three diagonalizable transformations on finite-dimensional vector space which satisfy the following condition. The eigenspaces can be ordered so that each transformation raises other two in block-bidiagonal fashion. show eigenvalue sequences associated to same recurrence relation. Based solutions this we define ...