Symmetrie-Symbole

Site symmetry symbols, I, 128 Six-coordinate compounds stereochemistry, 1, 49-69 Six-membered rings metal complexes, 2, 79 Skeletal muscle sarcoplasmic reticulum calcium pump, 6, 565 Slags... 

Fig. 17. Calculated conformations (top and side views, drawn to scale) of cyclohexane (force field of ref. (79) outer values bond lengths in A and angles in degrees, inner values torsion angles). The quantities below the symmetry symbols are calculated A V- and AH-values (kcal mole-1 T = 298 K reference chair conformation)...

What are the symmetry symbols for the bonding and antibonding orbitals of H2 ... 

In the discussion of the bonding of the E2 molecules in the next section, the orbitals are referred to by their symmetry symbols with the appropriate numerical prefixes. 

Figure 11.4. The symmetry elements of the five 2D lattices. For each pair the lattice is represented on the left by the points defining one unit cell and on the right are the symmetry elements. Different orientations of the symbols are used to differentiate nonequivalent axes of the same order. Symmetry symbols in parentheses are redundant, that is, indicate those that arise automatically from those preceding them.

Figure 2 Simplified MO energy pattern for cubanoid (P3-X)4M4L4 clusters, emphasizing the key MOs B, N, A. The numerals give the number of MOs of each type, and the symmetry symbols are for point-group Tj...

To make matters even more complicated, it is much more convenient in crystallography to use an entirely different system of symmetry symbols, termed the Herman-Maugin (as opposed to Schoenflies) notation (Table 8.2). 

There is another type of symmetry element that, though less common than simple planes and axes, is nonetheless useful. If a molecule has a center of symmetry (symbol i, located at its center of mass), every atom in the structure has an indistinguishable companion atom located the same distance from the center, along a line through the center connecting the atoms. Though it lacks any planes or axes of symmetry, structure 4-6 has a center of symmetry. Do you see how each pair of companion atoms (carbons, hydrogens, chlorines, and bromines) are equivalent by virtue of the i ... 

A molecule has a center of symmetry (symbol i) when every atom in the structure has an indistinguishable companion atom located the same distance from the center, along a line through the center connecting the atoms. 

A more flexible but less explicit notation, due to Mulliken, is also employed-Here the MO s are simply labelled z, y, x, w, v, u,. .., in ascending energy order, the symmetry symbols or, jr, 5,. .. being added as required. Thus, for example, za is used for the a2s MO, inner shells being omitted. With this notation and the principles already put forward, electronic structures may be described along the following lines ... 

Priming convention. The configuration index is especially useful for bis(tridentate) complexes and for more complicated cases. Bis(tridentate) complexes exist in three di-astereoisomeric forms which serve to illustrate the utility of a priming convention. These isomers are represented below, along with their site symmetry symbols and configuration indexes. For Examples I, 2, and 3, the two ligands are identical and the ligating-atom priority numbers are indicated. 

Headline. Provides the short international (Hermann-Mauguin) space group symmetry symbol (Cmm2) followed by the SchOnflies symbol of... 

Symmetrie-Symbole Die Bezeichnungen in den Molekiilorbital-Diagrammen stammen aus der Gruppentheorie und beschreiben die Symmetrie und den Entartungsgrad der Molekiilorbitale a, b einfach entartete Orbitale... 

---