applicability of such refinements, and itis so approximate, that the effort hardly
seems worthwhile.
References
- Dixon SL, Jurs PC (1994) J Comp Chem 15:733
- Tajima S, Katagiri T, Kanada Y, Nagashima U (2000) J Chem Softw 6:67–74 [in Japanese]
- Dixon SL, Merz KM (1997) J Chem Phys 107:879
- (a)Streitwieser A Jr (1961) Molecular orbital theory for organic chemists. Wiley, section 4.3.
(b) Roberts JD (1962) Notes on molecular orbital calculations. Benjamin, New York,
chapter 7
Chapter 4, Harder Questions, Answers
Q8
Give the references to a journal paper that used the SHM, and one that used the
EHM, within the last decade. Give an abstract if each paper.
I have taken the liberty of giving the abstracts supplied by the author(s).
The SHM:
Kutzelnigg W (2007) J Comput Chem 28:25
What I like about Huckel theory.
Abstract
We start with some biographical notes on Erich Huckel, in the context of which
we also mention the merits of Otto Schmidt, the inventor of the free-electron model.
The basic assumptions behind the HMO (Huckel Molecular Orbital) model are
discussed, and those aspects of this model are reviewed that make it still a powerful
tool in Theoretical Chemistry. We ask whether HMO should be regarded as
semiempirical or parameter-free. We present closed solutions for special classes
of molecules, review the important concept of alternant hydrocarbons and point out
how useful perturbation theory within the HMO model is. We then come to bond
alternation and the question whether the pi or the sigma bonds are responsible for
bond delocalization in benzene and related molecules. Mobius hydrocarbons and
diamagnetic ring currents are other topics. We come to optimistic conclusions as to
the further role of the HMO model, not as an approximation for the solution of the
Schrodinger equation, but as a way towards the understanding of some aspects of
the Chemical Bond.
The EHM:
Raza H, Kan EC (2008) Los Alamos National Laboratory, Preprint Archive,
Condensed Matter, 1–5, arXiv:0801
Abstract
618 Answers