Primitive Description

Orthorhombic Hexagonal Trigonal (Rhombohedral) Monoclinic Tri clinic The primitive description of the rhombohedral lattice P, C, I, F P P/R P, c P is normally given the symbol R. 

In order to describe the number of primitives and contractions more directly, the notation (6s,5p) (ls,3p) or (6s,5p)/(ls,3p) is sometimes used. This example indicates that six s primitives and hve p primitives are contracted into one s contraction and three p contractions. Thus, this might be a description of the 6—311G basis set. However, this notation is not precise enough to tell whether the three p contractions consist of three, one, and one primitives or two, two, and one primitives. The notation (6,311) or (6,221) is used to distinguish these cases. Some authors use round parentheses ( ) to denote the number of primitives and square brackets [ ] to denote the number of contractions. 

Fig. 4. (a) The seven primitives of the triangular description of trends (b) sequence of triangular episodes describing a specific trend of a signal. 

The above description provides a possible starting background for the description of the beginning of cellular chemotypes, prokaryotes, but even this is less complicated than the only cells for which we have evidence since they have at least two additional groups of more sophisticated chemicals - coenzymes (see Tables 5.3 and 5.4) and certain metal cofactors, which we presume were additions to the most primitive cells. After we have described them, we shall return to the problem of cellular (cytoplasmic) organisation. Note that coenzyme novelty is not in basic pathways but in control of rates and in energy management. 

We now turn to transport properties of electrolytes. As mentioned above this problem is much more complicated than the equilibrium one because the solvent plays a crucial role in the description of dissipative phenomena. As a matter of fact, no general solution exists to this problem, because the statistical description of the liquid state is still at a very primitive stage. 

Description of a rhombohedral unit cell in terms of the equivalent, triple-primitive, hexagonal cell (see Fig. 3.9). 

A detailed example of the alternative descriptions of a given compound, both in terms of its hexagonal unit cell and of the corresponding rhombohedral primitive cell is presented in Chapter 4 the rhombohedral compound Mo6PbSx (the prototype of the family of the so-called Chevrel phases) is described and unit cell constants and atomic positions are listed for its conventional hexagonal cell and for the rhombohedral primitive cell. 

Description of a cubic (primitive, body centred or face centred) unit cell (ac) in terms of the equivalent, primitive rhombohedral, (a,-, a) and triple-primitive hexagonal, cells (ah, ch). See Fig. 3.11. 

The term modeling refers to a process of determining an appropriate description of reality that approximates its behavior to some specified degree of accuracy. Models are constructed using well-understood primitive components, or building blocks, defined by their inherent functionality and also their interaction mechanism. 

The guiding principle in writing down the self-repelling Gaussian chain model is mathematical simplicity, not microscopic faithfulness. Do we have, any idea why such a primitive model properly can explain the experiments To investigate this question we consider how a realistic microscopic description could be reduced to our model. 

---