Introduction
USPEX is a structure prediction code developed by the Oganov laboratory since 2004. The problem of crystal structure prediction is very old and does, in fact, constitute the central problem of theoretical crystal chemistry. In 1988 John Maddox wrote that:
One of the continuing scandals in the physical sciences is that it remains in general impossible to predict the structure of even the simplest crystalline solids from a knowledge of their chemical composition solids such as crystalline water (ice) are still thought to lie beyond mortals’ ken.
USPEX code solves this problem and allows to predict crystal structure with arbitrary P-T conditions by knowing only chemical composition of the material. Nowdays, it is used by over 6000 researchers worldwide.
In addition to crystal structure prediction, USPEX can work in other dimensionalities and predict the structure of nanoparticles, polymers, surfaces, interfaces and 2D-crystals. It can very efficiently handle molecular crystals (including those with flexible and very complex molecules). Moreover, it can predict stable chemical compositions and corresponding crystal structures, given just the names of the chemical elements. In addition to this fully non-empirical search, USPEX allows one to predict also a large set of robust metastable structures and perform several types of simulations using various degrees of prior knowledge.
My role
I have been involved in the development of the USPEX since 2010 when I joined Prof. Oganov’s research group as the graduate student. I was also the chief developer of the USPEX code between 2012-2016. Several of my key contributions include the modules for organic crystals, surfaces, 2D crystals, polymers, and grain boundaries. Since I joined UNLV, I have been descreasing my efforts in developing the USPEX code. Instead, the group is more fousing on developping the PyXtal and PyXtal_FF. That said, my groups is still actively using the code for differnt research projects involving materials discovery and design.