Fyzikální ústav Akademie věd ČR

Václav Petříček, Michal Dušek, Lukáš Palatinus, Karla Fejfarová

Department of structure analysis has gained world-wide reputation in solution of difficult structures, which cannot be solved with automatic or semi-automatic methods and where standard crystallographic solution software may fail. We recognize following kinds of difficult structures:

Modulated structures
Composite structures
Multidomain samples of the same structure (twins)
Multidomain samples with different structures (multiphases)
Magnetic structures

Very often the properties are combined, for instance in modulated twins or modulated composites. Program Jana, which is being developed in the framework of the project Development of the computing system Jana is well recognized tool for calculation of difficult structures.

We provide support for researchers having troubles with structure determination of difficult structures. Such support can take form of an e-mail discussion, workshops or short term stays in our laboratory in Prague sometimes connected with remeasurement of the sample. Usually such collaboration concerns very interesting samples not investigated in the Czech Republic, enriching and accelerating development of the computing system Jana.

Selected results:

H. Krüger, V. Kahlenberg, V. Petříček, F. Phillipp, W. Wertl. High-temperature structural phase transition in Ca2Fe2O5 studied by in-situ X-ray diffraction and transmission electron microscopy. J. Solid State Chem. 182 (2009) 1515 - 1523.

E. Makovicky, V. Petříček, M. Dušek, D. Topa. Crystal structure of a synthetic tin-selenium representative of the cylindrite structure type. Am. Mineral. 93 (2008) 1787 - 1798.

D. Topa,V. Petříček, M. Dušek, E. Makovicky, T. Balic-Zunic. Simultaneous refinement of two components of an exsolution intergrowth: Crystal structures of the lindstromite-krupkaite pair. Can. Mineral. 46 (2008) 525 - 539.

P. Kopel, J. Kameníček, V. Petříček, A. Kurečka, B.Kalinska, J. Mrozinski. Syntheses and study on nickel and copper complexes with 1,3,5-benzenetricarboxylic acid. Crystal and molecular structure of [Cu3(mdpta)3(btc)](ClO4)3 .4H2O. Polyhedron 26 (2007) 535 - 542.

M.A. Zhuravleva, M. Evain, V. Petříček, M.G. Kanatzidis. GdCo1-xGa3Ge: Charge density wave in a Ga square net. J. Am. Chem. Soc. 129 (2007) 3082 - 3083.

L. Bindi, M. Dušek, V. Petříček, P. Bonazzi. Superspace-symmetry determination and multidimensional refinement of the incommensurately modulated structure of natural fresnoite. Acta Crystallogr. B 62 (2006) 1031 - 1037.

L. Bindi, V. Petříček, R.L. Withers, M. Zoppi and P. Bonazzi. A novel high-temperature commensurate superstructure in a natural bariopyrochlore: A structural study by means of a multiphase crystal structure refinement. J. Solid State Chem. 179 (2006) 729 - 738.

M. Evain, V. Petříček, Y. Moëlo, C. Maurel. First (3+2)-dimensional superspace approach to the structure of levyclaudite-Sb), a member of the cylindrite-type minerals . Acta Crystallogr. B 62 (2006) 775 - 789.

O. Mentré, E.M. Ketatni, M. Colmont, M. Huvé, F. Abraham, V. Petříček. Structural features of the modulated BiCu2(P1-xVx)O6 solid solution; 4-D treatment of x=0.87 compound and magnetic spin-gap to gapless transition in new Cu2+ two-leg ladder systems. J. Am. Chem. Soc. 128 (2006) 10857 - 10867.

V. Petříček, E. Makovicky. Interpretation of selected structures of the bismuthinite - aikinite series as commensurately modulated structures. Can. Mineral. 44 (2006) 189 - 206.

L. Palatinus, M. Dušek, R. Glaum, E.B. Brahim. The incommensurately and commensurately modulated crystal structures of chromium(II) diphosphate. Acta Crystallogr. B 62 (2006) 556 - 566.

V.Petříček, M.Dušek, J.Černák. Modulated one-dimensional structure of [Cd(NH3)3Ni(CN)4]. Acta Crystallogr. B 61 (2005) 280 - 286.