Wednesday, August 27, 2008


Currently listening to: Bon Iver- For Emma, Forever Ago

I'm currently sorting out scads and scads X-ray absorption spectra from our recent trip to the Canadian Light Source. It's slow going (loads of calibrations with standards, bleh, sorry jöns, but that's really not my cup of tea).

Anyway, I thought I'd take a short break to give a shout out to Matt Newville, genius and creator of the IFEFFIT software suite I'm using to crunch numbers.[1]

IFEFFIT is an open-source set of tools for the X-ray spectroscopist, namely for XAFS, though it is very powerful for NEXAFS/XANES as well. For those of you scratching your heads about all of those acronyms, XAFS--aka, "X-ray Absorption Fine Structure"--is a spectroscopic technique for element-specific information on bonding, coordination number, etc. You can use it on compounds where you normally could not do X-ray crystallography/ EELS/RHEELS- gases and liquids, all kinds of amorphous stuff (including nanomaterials) and even on things like surfaces (that's called SEXAFS).

Analogously to crystallography, XAFS can be incredibly mathematically complex and involves a ton of modelling. Newville's software has some bad boy meaty algorithms for dealing with that buffet of data.

The cool thing about IFEFFIT is that Newville (and the other developers, listed below) are actual users and scientist who have successfully used this technique. XAFS requires a lot of number-crunching, but it also needs a keen chemical intuition. Newville has a long list of publications where he's looked a lot of actual chemistry problems.

IFEFFIT also has a very strong user community, where you can post questions and get smart answers quickly-- sometimes even from Newville himself.

It's a huge help to me in my research, and all in all I imagine the software development to be somewhat of a thankless job when you're giving it away for free(for comparison's sake, another piece of software I use quite a bit, ChemDraw, wants me to pony up at least $800 to draw pretty pictures! And don't even get me started on the other tools of the trade. Sheesh!) Hats off to you, Matt Newville.

[1] Other significant contributors to XAFS data processing are Bruce Ravell (who developed the GUI for IFEFFIT you see above on my mac ), Sam Webb and Shelly Kelly.

1 comment:

Jons said...

no appreciation for standards and calibrations! Why that's heresy!