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Adam R. Johnson, Harvey Mudd College
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Joined: 11/17/2007 - 10:55am

SYMMETRY CHALLENGE!

Symmetry Challenge!
A contest across VIPEr, the Virtual Inorganic Pedagogical Electronic Resource.

Here is a chance to show your symmetry skills to all the inorganic chemists and students of inorganic chemistry on ionicviper.org!

Given a cube and 6 equal length lines how many objects of different point group symmetry can you construct?  All six lines must fit either edge to edge or vertex to vertex (it is ok to mix and match if you want), and each face must have one and only one line on it.

The student who comes up with the most examples of different point groups (you only get credit for one object from each point group) wins!  Send me an email using the contact info on my profile on this website with your submission.  For the 2009 contest, submissions are due March 13th.  The prize is a selection of fun VIPEr products including your own snake mascot, and the opportunity to be prominently featured on the VIPEr home page!

Here are two to get you started:
a)  the 6 lines go vertex to vertex, it is a tetrahedron inscribed in a cube with Td symmetry

OBJECT1.png

b)  a mixture of edge to edge and vertex to vertex, this object has Cs symmetry

object2.png

How many more can you come up with?

Joanne Stewart, Hope College
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I love this and have a question. In example b, the 6 lines aren't all the same length. Is that okay?
Adam R. Johnson, Harvey Mudd College
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that is correct.  The lines need not all be the same length, but there must be one line on each face of the cube.
Anne Bentley, Lewis & Clark College
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Adam, What do you think is the best format for sumbissions? Drawings of each "structure" made with a drawing program? Text descriptions? What can we do to help you sort through submissions more easily? -Anne
Adam R. Johnson, Harvey Mudd College
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given the *huge* onslaught of submissions so far (zero) I don't think it matters, but for ease, a drawing along with a text description.  you could scan them in if they are handwritten?
Adam R. Johnson, Harvey Mudd College
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For registered users with "faculty status" and higher, the answers are now posted in the problem set section.  Please post comments if there is an incorrect point group assignment (embarrassing) or an obvious missing point group (likely) or another interesting example of a point group (likely).
Joanne Stewart, Hope College
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Adam, I looked at the answer key and was impressed by all of your drawings. That would have taken me forever.

You said that you got about 15 submissions that were mostly wrong, BUT WAS THERE A WINNER?

Adam R. Johnson, Harvey Mudd College
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Joined: 11/17/2007 - 10:55am

Lewis and Clark college had the most submissions, but Northern Kentucky won with the most correct answers.

tune in next year!