Alternative symbols

Alternative symbols are given for the particles often it is sufficient to use the simplest (the one on the right). Electron capture is not nuclear radiation but is included for completeness. 

In Table 3-6.1 we give the essential symmetry elements for the various point groups. We use the word essential since some of the symmetry elements listed in this Table for a given point group will neoessarily imply the existence of others which are not listed. In Table 3-6.2 some alternative symbols are shown. An exhaustive list of... 

The list of alternate symbols arises because at an earlier stage in the history of X-ray crystallography, it was the accepted convention to call the unique axis b. The reader can easily see that if this is done, the alternate symbols become correct. Since in the other crystal systems with a unique direction (i.e., tetragonal and hexagonal) the unique direction is called c, the formally correct practice is now to do the same for the monoclinic system. However, the literature is still replete with the old choice of axes and it is necessary to be cognizant of both systems and of their relationship. 

The bond enthalpy, AH°(X-Y), of the X-Y bond (sometimes called, bond dissociation enthalpy or, loosely, bond energy and sometimes given the alternative symbols is (X-Y) or BEx-y) is a quantitative (thermochemical based) description of the average enthalpy required to break an X-Y bond. 

Figure 1.8. From left to right horizontal two-fold rotation axis (top) and its alternative symbol (bottom), diagonal three-fold inversion axis inclined to the plane of the projection, horizontal four-fold rotation axis, horizontal, and diagonal mirror planes. Horizontal or vertical lines are commonly used to indicate axes located in the plane of the projection, and diagonal lines are used to indicate axes, which form an angle other than the right or zero angles with the plane of the projection.

The alternative symbols in Table 4.2 indicate the numbers of layers in the repeat units also the layer sequence may be derived directly from the symbol. The change from A - B- C is represented as a unit vector +1 and in the reverse direction as — 1. A succession of n positive (or negative) units is abbreviated to n ( ), so that 22 stands for 1111. .. and starting from/4 gives the sequence B CB A. 

Accepted Meaning Alternatives Symbol Name Symbol Name ... 

The underline is used only in the definition of the function. It is not used after the symbol for the function s argument in an expression. Note that Mathematica uses square brackets for the argument of a function, not parentheses. The rules of Mathematica must be followed exactly. There is no provision for alternative symbols. 

For example, the crystal class for I4c2 is 4m2, an alternative symbol for 42m. The crystal system is tetragonal and the Bravais lattice is tetragonal I. 

The alternative symbol for the liter, L, was adopted by the CGPM in order to avoid the risk of confusion between the letter 1 and the number 1. Thus, although both 1 and L are internationally accepted symbols for the liter, to avoid this risk the symbol to be used in the United States is L. The script letter is not an approved symbol for the liter. 

Bioclastic sand—BSW, BSP, BSM, BSC, Alternate symbols are CaSW, CaSP, CaSM and CaSC. 

Bioclastic gravel—BGW, BGP, BGM, BGC, Alternate symbols are CaGW, CaGP, CaGM, and CaGC. 

Bioclastic sand—BSW, BSP, BSM, BSC, Alternate symbols are CaSW, CaSP, CaSM, and CaSC Bioclastic gravel—BGW, BGP, BGM, BGC, Alternate symbols are CaG W, CaGP, CaG L and CaGC... 

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