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Introduction Structure analysis of modulated structures has become well established field of crystallography [ 1 , 2 ]. The superspace theory as formulated by de Wollf et al. [ 3 ] has proven to be the best tool to generalize methods originally developed for solution and refinement of regular structures, and to apply them for calculation of modulated and composite structures. In these systems any structural parameter (occupancy, atomic coordinates and atomic displacement parameters – ADP) can be expressed as a periodic modulation function of the internal

The Modulated Structure of SrAuSn2 Saeid Esmailzadeha, Rolf-Dieter Hoffmannb, and Rainer Pöttgenb a Department of Inorganic Chemistry, Arrhenius Laboratory, Stockholm University, SE–106 91 Stockholm, Sweden b Institut für Anorganische und Analytische Chemie, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, D-48149 Münster, Germany Reprint requests to R. Pöttgen. E-mail: Z. Naturforsch. 59b, 1451 – 1457 (2004); received August 24, 2004 Dedicated to Professor Hubert Schmidbaur on the occasion of his 70th birthday The

far, no temperature-dependent diffraction experiments and only preliminary physical property studies have been reported [37–41]. In extension of our detailed studies on CeRuSn we have recently investigated the CeCoAl structure [42]. The aluminide shows a second-order phase transition at 271 K and the low-temperature structure can be described in the (3+1)D space group C 2/ m (α0γ)00 with q =(2/3, 0, 2/5). Again, the striking crystal chemical features are short Ce–Co distances. The modulated structure of the higher congener CeCoGa is reported herein. Experimental

Zeitschrift für Kristallographie 201, 9-17 (1992) © by R. Oldenbourg Verlag, München 1992 - 0044-2968/92 $ 3.00 + 0.00 Statistical analysis of incomniensurately modulated structures — example NbTe4 J. Kusz* and H. Böhm Institut für Geowissenschaften der Universität, D-6500 Mainz, Federal Republic of Germany Dedicated to Prof. F. Liebau on the occasion ofhis 65th birthday anniversary Received: November 27, 1990; in final form July 14, 1991 Modulated structure / Short range model / NbTe4 Abstract. The solution of incommensurately modulated structures is con

Introduction Plagioclase feldspars, which form a coupled solid solution between albite (Ab; NaAlSi 3 O 8 ) and anorthite (An; CaAl 2 Si 2 O 8 ), are the most abundant group of minerals in the Earth’s crust, and they can be found in most igneous and metamorphic rocks. However, the complicated crystal structure and subsolidus phase relation has been puzzling mineralogists for decades. The most enigmatic feature of plagioclase is the incommensurately modulated structure ( e -plagioclase) that appears in low plagioclase with composition between ~An 25 and ~An 75

Flexible phases, modulated structures and the transmission electron microscope Ray L. Withers*, Lasse Norén and Yun Liu Research School of Chemistry, Australian National University, Canberra, A.C.T, 0200, Australia Received March 23, 2004; accepted June 28, 2004 Modulated structures / Electron microscopy / Flexible phases / Interface, composite and displacively modulated phases / Superspace symmetry / Incommensurate structures Abstract. A review of the application of transmission electron microscopy to the study of interface, composite and displacively modulated

Zeitschrift für Kristallographie 171, 41-64 (1985) © by R. Oldenbourg Verlag, München 1985 The modulated structure of niobium tetratelluride NbTe4 Horst Böhm* and Hans-Georg von Schnering Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany Received: September 15, 1984 In memoriam Professor A. Niggli NbTe4 I Modulated structure / Incommensurate phase / Discommensuration Abstract. The well known tetragonal NbTe4 structure was refined (7? = 0.047; 186 independent reflections). In this average structure

MS LR6 ΤΗ Modulated structures, polytypes and quasicrystals Gratias D., Vitry sur Seine Janssen Τ., Nijmegen MSI ΤΗ 90 N-dimensional crystallography applied to quasicrystals Kramer P. MS2 TH 91 Incommensurate structures Smaalen S. van, Boer J. L. de MS3 ΤΗ 92 N-dimensional structure analysis Steurer W. MS4 TH 93 Modulated structures in liquid crystals Levelut A. M. MS 5 TH 94 On the axial next nearest neighbor Ising model Finel A. Zeitschrift für Kristallographie 185. 90 (1988) - MSI TH © by R.Oldenbourg Verlag, München 1988 90 N

10% (e.g. [5, 6]) and the corresponding s-satellites, first observed by Jagodzinski and Korekawa [7], have been analysed quantitatively with respect to their intensities [8] and profiles [9]. Almost triangular displacements of rigid unit cells and varying lamellar thicknesses have been found. These results have been obtained by applying an extended version of Korekawa’s [10] original satellite theory. They will be supplemented here briefly by applying the general program package for modulated structures JANA2006 [11]. Fig. 1: (A) Schematic drawing of the lamellar

American Mineralogist, Volume 94, pages 728–736, 2009 0003-004X/09/0506–728$05.00/DOI: 10.2138/am.2009.3159 728 The role of silver on the stabilization of the incommensurately modulated structure in calaverite, AuTe2 Luca Bindi,1,* aLLa arakcheeva,2 and Gervais chapuis2 1Museo di Storia Naturale, Sezione di Mineralogia, Università di Firenze, Via La Pira 4, I-50121 Firenze, Italy 2École Polytechnique Fédérale de Lausanne, Laboratoire de Cristallographie, BSP, CH-1015 Lausanne, Switzerland aBstract Structural investigations of several minerals belonging to