The evolutionary methodology USPEX for crystal structure prediction [1] provides, with high reliability and efficiency, the stable and low-energy metastable structures of a given compound at given P-T-conditions. Theory of energy landscapes of solids [2] gives tools that greatly enhance structure prediction. The following results will be discussed:1. Theoretical and experimental evidence for a new stable high-pressure phase of boron, ?-B [3], showing superhardness and charge transfer between boron.2. New high-pressure phase, a transparent insulator, was found for sodium [4].3. High-pressure phases of group IV hydrides � methane CH4 [5], silane SiH4 [6], germane GeH4 [7] and stannane SnH4 [8]. We found much more stable phases of SiH4 and SnH4 than previous random-sampling predictions, and unusual structure of the superconducting phase of GeH4 with high Tc= 64. CH4 decomposes into diamond and hydrogen within interiors of giant planets; this process is important for understanding the energy balance of Neptune.Our method has been extended to enable efficient prediction of the structure of nanoparticles and surface reconstructions, which opens doors for many geochemical applications, as well as predictive studies of nanomaterials and catalysis. References[1] Oganov A.R., Glass C.W., J.Chem.Phys. 124, 244704 (2006)[2] Oganov A.R., Valle M., J.Chem.Phys. 130 , 104504 (2009)[3] Oganov A.R., Chen J., Gatti C., et al., Nature 457 , 863 (2009)[4] Ma Y., Eremets M.I., Oganov A.R., et al., Nature 458 , 182 (2009)[5] Gao G., Oganov A.R., et al., J.Chem.Phys. 133 , 144508 (2010).[6] Martinez-Canales M., Oganov A.R., et al., Phys.Rev.Lett. 102 , 087005 (2009)[7] Gao G., Oganov A.R., et al., Phys.Rev.Lett. 101, 107002 (2008).[8] Gao G., Oganov A.R., et al. (2010). Proc.Natl.Acad.Sci. 107 , 1317 (2010).

Evolutionary crystal structure prediction as a tool for finding new forms of matter

243rd National Meeting (2012)

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