Dear
CCL'ers For many years now a few theoretical chemists
(Primas, Woolley, Sutcliffe) have claimed that there is something significant
going on in connection with the Born-Oppenheimer approximation.
They claim that applying the approximation
amounts to writing the structure of a molecule in 'by hand' rather than the
structure being inherent in the quantum formalism.
They cite examples such as C2H5OH and CH3OCH3
which share the same Hamiltonian and conclude that structure cannot therefore be
deduced from QM in an ab initio fashion. Some
philosophers of chemistry have taken this a good deal further as a sign that
chemistry (molecular structure) cannot be strictly reduced to quantum mechanics.
Some even claim that there is 'emergence' taking place.
Most chemists I have discussed this issue with
claim that these philosophers and even the theoretical chemists mentioned above
are reaching incorrect conclusions. Most chemists claim that structure
does really exist as a matter of fact and that we could in principle solve the
Schrodinger equation without fixing the position of the nuclei by solving the
equation for every conceivable arrangement and would thereby recover the
inherent structure. I would be interested in
comments and have a follow-up question if there is any interest in this topic.
all the best, eric
scerri Eric Scerri,
The Periodic Table, Its Story and Its Significance, Oxford University Press,
2007 |