Test

We test tex:

[math]\displaystyle{ F_{hkl} = \sum_{i=1}^{N} e^{-2\pi\imath\left( h\frac{x}{a}+k\frac{y}{b}+l\frac{z}{c}\right)} }[/math]

test

All crystals should look like this (or better)

Problem? - I tried uploading xtals.png but Wiki does not let me upload, quoting that 'wrong file type or extension' - yet it allowed me to load up the same image in jpg format. Png is a nice (some would even say the best) format so it'd be good to be able to use it! -AGE