A new boron allotrope

[bobthemole]

This article reminds me why I first fell in love with chemistry, It's also an exceptionally well-written piece of science journalism:

Boron’s unusual properties come from the three electrons in its outer electronic layer. For similar elements like aluminum, one row down on the periodic table, the three outer electrons are easily torn away, and the element behaves as a metal. But boron is smaller, and so its nucleus holds on to the electrons tighter, more like an insulator.

“Boron is a truly schizophrenic element,” Dr. Oganov said. “It’s an element of complete frustration. It doesn’t know what it wants to do. The outcome is something horribly complicated.”

And here's the really cool part...

Starting with a number of trial crystal structures, the program calculates the energy needed to hold each together, and discards the versions that do not pack together comfortably. Then, as occurs in biological evolution, the crystal parameters are tweaked (the equivalent of mutation) and portions of the structure swapped (the equivalent of recombination). After generations of calculation, the answer converges on the stable form.

This algorithm had previously revealed new phases of iron sulfide, calcium carbonate, sulfur and even a superconducting form of oxygen, subsequently confirmed by experiment.

Comments

[peribothron.livejournal.com]

Yes, that was a good article.
Also, for a good 're-up' of the joy of science, have a listen to this episode of RadioLab:
http://www.wnyc.org/shows/radiolab/episodes/2008/12/12
(Krulwich is the the guy who did the Tech commencement last summer.)

[peribothron.livejournal.com]

see my latest post.