[Phys-l] Models and Pictures of Atomic Wavefunctions

[John Denker <jsd@av8n.com>]

[cross-posted from the chemistry list]

On 10/11/2010 09:29 AM, Renee Judd wrote:

> The textbook I am using for liberal arts chem discusses electron
> configurations. I thought, given the lovely resources on the web for
> orbitals, it would be nice to supplement this with graphic
> representations of atomic orbitals. I like using color to indicate
> the various phases, but most text descriptions use plus and minus to
> designate the phases. I have just got through to MOST of the students
> that electrons have a negative charge. I do not want orbital lobes
> labeled or described as plus or minus. Does anyone have better
> language to use with introductory students?

In response to various questions and suggestions, off-list and on-,
I have substantially upgraded this document:
  http://www.av8n.com/physics/wavefunctions.htm

There is a lot more detail on "rope tricks"
  http://www.av8n.com/physics/wavefunctions.htm#sec-string

including a discussion of 
 -- how to demonstrate running waves as well as standing waves,
 -- why you can /sometimes/ get away with labeling various parts 
  of a wavefunction as "plus" and "minus", but why this is always 
  risky and often impossible, and
 -- the importance of using the string demos in tandem with the 
  tub-of-water demos, to give a much more complete picture.

There is also a new section
  http://www.av8n.com/physics/wavefunctions.htm#sec-running

which provides some new multi-dimensional animations portraying
(among other things) the phase and amplitude of the wavefunction
ordinate for the |2p+> wavefunction.  The animation makes it quite
obvious that this is a running wave.

These animations are something I've wanted for a long time.  I've
had the picture in my mind's eye.  All too often, when it comes 
to abstract things like wavefunctions, I can visualize more things 
than I can capture in a diagram ... but these diagrams came out 
the way I wanted them to.  On the third hand, there's a lot more 
that could be done along these lines.  For example, I would like 
to apply the same technique to the |2px> orbital, but that would 
take a bunch of additional work.

> I like using color to indicate the various phases

Done.

>  I do not want orbital lobes labeled or described as plus or minus.

Done.  No labels.  Indeed, no lobes!