BX1413 Instructuional Aid

[Graheme Williams]

With reference to the posting of last Friday concernig the availability of 
"a series of 1-dimensional electron density maps on transparancies which stack
together to from a benzene ring"   I offer the following:-

The description given is not quite right since the objects displayed on the 
transparancy sheets are PHASED WAVES of appropriate amplitude (displayed as a 
dot density pattern I recall) with one wave recorded per sheet.  There a 
something like a dozen sheets corresponding to a dozen components of the 
fourier synthesis of the pattern.  The sheets can be used to illustrate the 
features of phase, amplitude and summation in developing a Fourier synthesis. 
Another slight misunderstanding is that the summation is not really  that of a
benzene ring but it is the central portion of an infinite pattern of hexagons 
and so looks like a benzene  ring.

The person who I saw use this demonstration is Dr Henk Schenk of the University
of Amsterdam.   Henk is a very reasonable person and you might contact him by 
e-mail at  "U00082 at hasara5"   Yes I know that looks strange but that's what is
recorded in the listing.

Good luck,

Best wishes   =Graheme=

EEEE N   N Graheme J.B. Williams, :                               :EEEE N   N
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