Conventional representation

The nature of the bonding in amine-boranes and related adducts has been the subject of considerable theoretical discussion and has also been the source of some confusion. Conventional representations of the donor-... 

Conventional representation of a carbon atom (e.g. C-2 of D-glucose) in the Fischer projection. Representation (e) will be used in general in the present document. 

The notion of spare electrons derives from reading the usual conventional representation of bonds, and the tetravalency of carbon,... 

Figure 3.11 Conventional representations of the shapes of the p orbitals. They are used as approximate representations of both ip and tp2. The sign of tp is indicated by the shading. (Reproduced with permission from and M. J. Winter, Chemical Bonding, 1994, Oxford University Press, Oxford.)...

The conventional representation is a powerful and familiar shorthand for discussing reaction mechanisms, and will be used here for that reason with the proviso that its shortcomings must constantly be borne in mind [see, for example, Albery (1993)]. 

In a more conventional representation of the Periodic Table, the Stone subdivision is shown in Fig. 4.8. However, in this figure, according to the so-called s-d shear... 

The conventional representation. We can write Equation (66) explicitly as follows... 

Phosphorus can form five covalent bonds. The conventional representation of Pj (Pig. 10a), with three P—0 bonds and one P=0 bond, is not an accurate picture. In Pi four equivalent phosphorus-oxygen bonds share some double-bond character, and the anion has a tetrahedral structure (Fig. 10b). As oxygen is more electronegative than phosphorus, the sharing of electrons is unequal the central phosphorus bears a partial positive... 

Figure 9.1—Conventional representation of a lH NMR spectrum of an organic compound. Spectrum of butanone [CH1(C=0)CH2CH1] Superimposed is the signal integration that allows the relative areas of each type of proton present in the spectrum to be determined. The meaning of the abscissa will be explained further on.

Figure 16.1—Bar (fragmentation) spectrum and mass spectrum presented in graphical and tabular form. a) Bar spectrum of methanol b) non-conventional representation of the same spectrum in the form of a circular diagram for each 321 ions formed, there are statistically 100 ions of mass 31 u (Da), 72 of mass 29 u, etc. The various ions constitute different populations c) part of a high-resolution recording of compound M with two ions with very close m/z ratios (one due to loss of CO and the other due to loss of C2H4).

Kg- 2. Polar representation of periodic relationships of the elements. (Source Oumibix, U.SAJ) At upper right is shown the conventional representation, see the front matter for the current representation... 

The conventional representation of numbers using scientific notation is not always followed. For example, we might represent a bond length as 0.14x 10-9 m rather than 1.4 x 10-10 m if we were referencing it to another measurement of length given in integer unit multiples of 10 9 m. 

Operators corresponding to physical quantities, in second-quantization representation, are written in a very simple form. In the quantum mechanics of identical particles we normally have to deal with two types of operators symmetric in the coordinates of all particles. The first type includes N-particle operators that are the sum of one-particle operators. An example of such an operator is the Hamiltonian of a system of noninteracting electrons (e.g. the first two terms in (1.15)). The second type are iV-particle operators that are the sum of two-particle operators (e.g. the energy operator for the electrostatic interaction of electrons - the last term in (1.15)). In conventional representations these operators are... 

Maxwell s and wave equations in free space. As discussed elsewhere in the book, one can also question the validity of the conventional representation itself in this chapter, however, we will keep as close as possible to Maxwell s equations. Without any pretension for completeness, some of the issues are as follows. 

Fig. 4.8 The electron density is represented by the square of the mathematical function we call the orbital. A carbon 2p orbital is actually more buxom than its conventional representation, and two 2p orbitals overlap better than the usual picture, e.g. Fig. 4.7, suggests...

Figure 2 Conventional representation of micelles formed by an ionic surfactant, such as sodium dodecyl sulfate. The inner core region consists of the methylene tails of the surfactants. The Stem layer consists of surfactant headgroups and bound counterion species. The diffuse double layer consists of unbound counterions and coions which preserve the electrical neutrality of the overall solution. Also pictured are the transition moment vectors for the S-O stretching modes of sodium dodecyl sulfate.

ST03G. This is the conventional representation of Slater type orbitals using three Gaussians apiece. [41]... 

The structure of the zeolite faujasite is shown in following figure. In this convention representation the framework structure is shown without depicting, atoms directly. Each line represents an SiOSi or Si O Al connection. Four lines meet at tetrahedral vertices representing the positions of the four-coordinate Si or A1 atoms. Spacefilling models of this zeolite show that the pores can accommodate molecules up to about 750 pm in diameter. 

Skeletal formula The representation of an organic compound s carbon-to-carbon bonds by lines. A single line represents a single bond with double and triple lines for double and triple bonds, respectively. The carbon-to-hydrogen bonds are assumed but not shown apart from the outline, but other functional groups or elements use their conventional representation. 

The conventional representations of hybrid orbitals used in Fig. 1.15 are just as misleading as the conventional representations of the p orbitals from which they are derived. A more accurate picture of the sp3 hybrid is given by the contours of the wave function in Fig. 1.16. Because of the presence of the... 

When an olefin coordinates to a transition metal, the olefin n bond donates electrons to an empty metal orbital (donor bond) and the olefin n orbital accepts metal valence electrons from a filled metal atomic orbital (back-bond). Two molecular orbitals can describe the conventional representation of the metal-olefin bond as originally proposed by Dewar and modified by Chatt 7). 

The scattered intensity is usually represented as the total number of the accumulated counts, counting rate (counts per second - cps) or in arbitrary units. Regardless of which units are chosen to plot the intensity, the patterns are visually identical because the intensity scale remains linear and because the intensity measurements are normally relative, not absolute. In rare instances, the intensity is plotted as a common or a natural logarithm, or a square root of the total number of the accumulated counts in order to better visualize both strong and weak Bragg peaks on the same plot. The use of these two non-liner intensity scales, however, always increases the visibility of the noise (i.e. highlights the presence of statistical counting errors). A few examples of the non-conventional representation of powder diffraction patterns are found in the next section. 

The conventional representation of methane in two dimensions is given, and is applicable to saturated carbon in general,... 

Figure 1. MoOg octahedra in M0O3 (in the full 2-dimensional stmcture, each O atom is shared between 2 octahedra). The distortion of the real structure (a) is not shown in the conventional representation (b). Mo atom, O O atom...

It is too early to determine the impact of harmony theory. It appears to provide a nice linkage between statistical or probabilistic aspects of modeling and more conventional representations. To date, it has not been widely used or validated empirically. 

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