Chemical Pictures

The progress in computer technology during the last 10-15 years has enabled the performance of ever more precise quantum mechanical calculations related to structure and interactions of chemical compounds. However, the qualitative models relating electronic structure to molecular geometry have not progressed at the same pace. There is a continuing need in chemistry for simple concepts and qualitatively clear pictures that are also quantitatively comparable to ab initio quantum chemical calculations. Topological methods and, more specifically, graph theory as a fixed-point topology, provide in principle a chance to fill this gap. With its more than 100 years of applications to chemistry, graph theory has proven to be of vital importance as the most natural language of chemistry. The explosive development of chemical graph theory during the last 20 years has increasingly overlapped with quantum chemistry. Besides contributing to the solution of various problems in theoretical chemistry, this development indicates that topology is an underlying principle that explains the success of quantum mechanics and goes beyond it, thus promising to bear more fruit in the future.

For a long time students have sought out solved problems in addition to those provided as examples in the textbook. Sources of such problems are related texts and old homework and examination files, but these alternate sources are usually inconvenient to find and use. To meet this demand the author compiled in this supplement additional problems with detailed solutions, problems that are quite similar to those in the text.

Released in 1976 5 years after their second album Green Man and with a completely revised line up, Pictures From Cyclus 7 was not only Ache's best album, but the best Danish prog album period. I have heard quite a few bands from Denmark, Norway, et all and been hugely let down trying to find something along this album's lines of melodic disciplined progressive pop/rock with no self indulgence whatsoever. Ache had made two high quality if inconsistent psychedelic/progressive records in the form of De Homine Urbano and Green Man, but this line up of 6 musicians + lyricist Bo Lillesoe made what is the unbeatable album from the Nordic Realm.