Chemical understanding and

In general the information is quite specific to its own chapter, and little effort is made to describe parallel behavior between one metal and another, for example. Occasional excursions into descriptions of principles or mechanical explanations give what little sense of philosophical unity there is. A closer look at some of his descriptions will give us a truer feeling for the state of chemical understanding and what concepts were there and what were still lacking before the art could become more truly a science. 

In tackling problems of molecular and electronic structure such as those posed by these sulfur-bridged tetrametallic clusters, two approaches are possible. One is the construction, often heavily reliant upon symmetry arguments, of a general, essentially qualitative model intended to provide a broad description of a series of molecules the other is a detailed quantum mechanical study, at an appropriate level of theory, of individual molecules, followed by a search for generalization or patterns. A combination of both approaches is usually the most valuable for chemical understanding, and much effort along these lines has been expanded on cubane-type clusters and their derivatives. 

C.K. Jorgensen, Influence of rare earths on chemical understanding and classification 197... 

Today we benefit in many ways from chemical understanding and technologies. Each benefit, however, has risks associated with it. The risks and benefits of chemical processes and technologies affect us either directly or indirectly. Many people—either on their own, in groups, or through their elected government officials—assess these risks and benefits. They ask questions such as the following ... 

This book starts each chapter with a self-test to check on chemical understanding, and then proceeds to move through the subject matter, always within the context of current practice. Anyone able to pass well on the self-test can move onto the next chapter. I hope you will find the Glossary a useful reference source for a number of chemical terms. 

Firstly, the power of molecular graphics to improve our chemical understanding and to derive qualitative structure property relation(QSPR) will be described. Molecular graphics is also useful for visual representation of the geometry of chemical systems during energy minimization and molecular dynamics calculations. 3-d representation of the results of quantum chemical calculations such as MO contour, electron density and electrostatic potential are effective ways of getting chemical information from the pile of numbers. 

INFLUENCE OF RARE EARTHS ON CHEMICAL UNDERSTANDING AND CLASSIFICATION... 

---