Subject: Re: CCL:Orbitals

From: Sengen Sun <sengensun|at|yahoo.com>
Date: Thu, 29 May 2003 10:21:26 -0700 (PDT)

E. Lewars wrote:

 If MOs have no physical reality for multielectron
species, why (a) is Koopmans' theorem useful, why (b)
do photoelectron spectra match the predictions of MO
energy-level diagrams, and why (c) does the Hueckel
4n+2 rule, which is based on MO diagrams, work? 

These are extremely interesting questions to me. They
are very difficult to be answered, as implied by two
very prominent theoretical physicists in the last
century   Gell-Mann and Feynman: 
http://www.prometheus.demon.co.uk/02/02kumar.htm

I agree with Scerri, Spanget-Larsen, and many others
that MOs have no physical reality. But I don t think
that we, as suggested by Feynman, should stop asking
why MOs are so powerful for predictions in chemistry.
If we stop thinking, we would accept the control of
the universe by something of no physical reality; And
we would not be able to achieve a real understanding
of chemistry and the universe; And we would have
conceptual or logical conflicts... 

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