Subject: orbital observation/latest suggestion

From: Eric Scerri <[email-masked]>
Date: Fri, 11 Aug 2000 19:19:45 -0800

Dear List members ,

A few days ago I posted an article I have written on the 
impossibility of observing orbitals which is due to appear in Journal 
of Chemical Education.

I also posted this on another list and received the following 
response.  I would like to ask the computational community whether 
they think there may be anything to this.  It will require 
calculating the contribution to the ground state of copper (I) oxide 
made by the configuration given below.  My own hunch is that this 
will not work but I have to confess that this seems plausible.

Of course even if this argument is correct it still does not 
represent the observation of a single orbital such as dz2 in Cu(I) 
oxide as claimed in the Nature article, editorial and other popular 
science magazines.

What it would presumably represent is the observation of the electron 
density due to all the combined densities due to all the Cu orbitals 
in Cu(I)oxide.

So what I am requesting is for someone to do a C.I. calculation to 
see the extent to which the 4s1 3d9 configuration contributes.  I 
would also be interested in general comments on this suggestion.

Here is the suggestion from a colleague.
------------------------------------------------------------------------
Only two electron configurations make substantial
contributions to the ground state in copper (I) oxide.  The major
contributor is the one we teach our freshmen for copper (I):  1s2 2s2 2p6
3s2 3p6 3d10.  Since this is closed-shell, the "combined effects of many
separate electron densities" is spherical about the copper nucleus.  Then
there is a small amount of configuration interaction with 3d9 4s1.  This
will have the shape of the singly-occupied d orbital.  To have the right
symmetry to mix with the closed-shell configuration, this must be dz2.

------------------------------

regards,

-------------------------------------------------
Eric Scerri PhD,
Editor of "Foundations of Chemistry"
http://www.wkap.nl/journalhome.htm/1386-4238