USPEX is a method developed jointly by Artem R. Oganov and Colin
W. Glass, Andriy O. Lyakhov and Qiang Zhu. This method/code enables
crystal structure prediction given just the chemical composition of
the material. It is based on an evolutionary algorithm that uses a
first-principles code (SIESTA included) to compute the enthalpies or
other relevant properties of the specimens considered.

The code has recently been released for public use (with
registration), and can be downloaded, together with the manual and
tests, from

http://han.ess.sunysb.edu/~USPEX/