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Twinning in chemical crystallography – a practical guide

  • Regine Herbst-Irmer EMAIL logo
Published/Copyright: May 31, 2016
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Zeitschrift für Kristallographie - Crystalline Materials
From the journal Zeitschrift für Kristallographie - Crystalline Materials Volume 231 Issue 10

Abstract

A non-negliglible percentage of crystal structures in chemical crystallography are derived from twinned crystals. The treatment of these data is dependent on the type of twinning. Twins by strict, pseudo or reticular merohedry may hamper space group determination and structure solution, while non-merohedral twins mainly hinder the data integration process. One structure determination of each type is described in detail. CsCp*Py (1) crystallizes in space group P65, mimicking 6/mmm symmetry by merohedral twinning. The data of IPr · AlI3 (2) (IPr=1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) simulate mmm symmetry although the true space group is P21/n. The crystals of K[Au(CN)2] (3) are obverse/reverse twins. [Cu3(dppaO2)2((OSiMe2)2O)2(thf)2] (4) (ddpaO2=bis(diphenylphosphoryl)amine) crystallizes in space group P21/n and is an example of a non-merohedral twin.

Keywords: chemical crystallography; refinement; solution; twin

Acknowledgments:

I thank Dietmar Stalke, Peter G. Jones, Richard J. Staples and Cornelia Göbel for the data collections of the described examples.

References

[1] M. G. Friedel, Sur les macles du quartz. Bull. Soc. Franc. Mineral. Cristallogr.1923, 46, 79.10.3406/bulmi.1923.3816Search in Google Scholar

[2] G. M. Sheldrick, A short history of SHELX. Acta Crystallogr. A2008, 64, 112.10.1107/S0108767307043930Search in Google Scholar PubMed

[3] F. Allen, The Cambridge Structural Database: a quarter of a million crystal structures and rising. Acta Crystallogr. B2002, 58, 380.10.1107/S0108768102003890Search in Google Scholar

[4] M. Nespolo, Tips and traps on crystal twinning: how to fully describe your twin. Cryst. Res. Technol.2015, 50, 362.10.1002/crat.201400422Search in Google Scholar

[5] R. Herbst-Irmer, G. M. Sheldrick, Refinement of twinned structures with SHELXL97. Acta Crystallogr. B1998, 54, 443.10.1107/S0108768197018454Search in Google Scholar

[6] R. Herbst-Irmer, G. M. Sheldrick, Refinement of obverse/reverse twins. Acta Crystallogr. B2002, 58, 477.10.1107/S0108768102001039Search in Google Scholar

[7] S. Parsons, Introduction to twinning. Acta Crystallogr. D2003, 59, 1995.10.1093/acprof:oso/9780199219469.003.0018Search in Google Scholar

[8] R. Herbst-Irmer, Twinning, In: Crystal structure refinement a crystallographer’s guide to SHELXL, (Ed. Peter Müller) Oxford University Press, Oxford, pp. 106, 2006.10.1093/acprof:oso/9780198570769.003.0007Search in Google Scholar

[9] T. Hahn, H. Klapper, Twinning of Crystals, In: International Tables of Crystallography Volume D: Physical Properties of Crystals, Vol. D, Second Edition. (Ed. A. Authier) International Union of Crystallography, Chester, p. 413, 2014.10.1107/97809553602060000917Search in Google Scholar

[10] C. Giacovazzo, Crystallographic computing, In: Fundamentals of Crystallography, (Ed.: C. Giacovazzo) IUCr/Oxford University Press, New York, p. 61, 2002.Search in Google Scholar

[11] W. Hönle, H. G. v. Schnering, Can X-ray crystal structure analysis decide between twinning by pseudo-merohedry and statistical distribution in YBa2Cu3O7? Z. Kristallogr.1988, 184, 301.10.1524/zkri.1988.184.3-4.301Search in Google Scholar

[12] M. Catti, G. Ferraris, Twinning by merohedry and X-ray crystal structure determination. Acta Crystallogr. A1976, 32, 163.10.1107/S0567739476000326Search in Google Scholar

[13] H. Flack, On enantiomorph-polarity estimation. Acta Crystallogr. A1983, 39, 876.10.1107/S0108767383001762Search in Google Scholar

[14] H. Klapper, T. Hahn, The application of eigensymmetries of face forms to anomalous scattering and twinning by merohedry in X-ray diffraction. Acta Crystallogr. A2010, 66, 327.10.1107/S0108767310001091Search in Google Scholar PubMed

[15] H. D. Flack, M. Wörle, Merohedral twin interpretation spreadsheet, including command lines for SHELXL. J. Appl. Crystallogr.2013, 46, 248.10.1107/S0021889812044974Search in Google Scholar

[16] E. Stanley, The identification of twins from intensity statistics. J. Appl. Crystallogr.1972, 5, 191.10.1107/S0021889872009185Search in Google Scholar

[17] D. Rees, The influence of twinning by merohedry on intensity statistics. Acta Crystallogr. A1980, 36, 578.10.1107/S0567739480001234Search in Google Scholar

[18] D. Rees, A general theory of X-ray intensity statistics for twins by merohedry. Acta Crystallogr. A1982, 38, 201.10.1107/S056773948200045XSearch in Google Scholar

[19] T. Yeates, Simple statistics for intensity data from twinned specimens. Acta Crystallogr. A1988, 44, 142.10.1107/S0108767387009632Search in Google Scholar

[20] A. Duisenberg, Indexing in single-crystal diffractometry with an obstinate list of reflections. J. Appl. Crystallogr.1992, 25, 92.10.1107/S0021889891010634Search in Google Scholar

[21] R. A. Sparks, GEMINI, Bruker AXS Inc., Madison, 2000.Search in Google Scholar

[22] G. M. Sheldrick, Cell_Now, Georg-August-Universität, Göttingen, 2012.Search in Google Scholar

[23] CrysAlisPro, Rigaku, 2015.Search in Google Scholar

[24] Bruker AXS Inc., SAINT v8.30C, Bruker AXS Inst. Inc., Madison, 2013.Search in Google Scholar

[25] A. M. M. Schreurs, X. Xian, L. M. J. Kroon-Batenburg, EVAL15: a diffraction data integration method based on ab initio predicted profiles. J. Appl. Crystallogr.2010, 43, 70.10.1107/S0021889809043234Search in Google Scholar

[26] D. Britton, Estimation of twinning parameter for twins with exactly superimposed reciprocal lattices. Acta Crystallogr. A1972, 28, 296.10.1107/S0567739472000786Search in Google Scholar

[27] G. M. Sheldrick, XPREP, Georg-August-Universität, Göttingen, 2015.Search in Google Scholar

[28] V. Kahlenberg, Application and comparison of different tests on twinning by merohedry. Acta Crystallogr. B1999, 55, 745.10.1107/S010876819900590XSearch in Google Scholar PubMed

[29] J. E. Padilla, T. O. Yeates, A statistic for local intensity differences: robustness to anisotropy and pseudo-centering and utility for detecting twinning. Acta Crystallogr. D2003, 59, 1124.10.1107/S0907444903007947Search in Google Scholar

[30] O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard, H. Puschmann, OLEX2: a complete structure solution, refinement and analysis program. J. Appl. Crystallogr.2009, 42, 339.10.1107/S0021889808042726Search in Google Scholar

[31] G. M. Sheldrick, SHELXT – Integrated space-group and crystal-structure determination. Acta Crystallogr. A2015, 71, 3.10.1107/S2053273314026370Search in Google Scholar PubMed PubMed Central

[32] C. S. Pratt, B. A. Coyle, J. A. Ibers, Redetermination of the structure of nitrosylpenta-amminecobalt(III) dichloride. J. Chem. Soc. A1971, 2146.10.1039/j19710002146Search in Google Scholar

[33] G. Rabe, PhD thesis, Georg-August-Universität Göttingen, 1991.Search in Google Scholar

[34] S. Parsons, H. D. Flack, T. Wagner, Use of intensity quotients and differences in absolute structure refinement. Acta Crystallogr. B2013, 69, 249.10.1107/S2052519213010014Search in Google Scholar PubMed PubMed Central

[35] R. S. Ghadwal, H. W. Roesky, R. Herbst-Irmer, P. G. Jones, N-Heterocyclic Carbene Adducts of Aluminium Triiodide. Z. Anorg. Allg. Chem.2009, 635, 431.10.1002/zaac.200801350Search in Google Scholar

[36] A. Spek, PLATON SQUEEZE: a tool for the calculation of the disordered solvent contribution to the calculated structure factors. Acta Crystallogr. C2015, 71, 9.10.1107/S2053229614024929Search in Google Scholar PubMed

[37] R. I. Cooper, R. O. Gould, S. Parsons, D. J. Watkin, The derivation of non-merohedral twin laws during refinement by analysis of poorly fitting intensity data and the refinement of non-merohedrally twinned crystal structures in the program CRYSTALS. J. Appl. Crystallogr.2002, 35, 168.10.1107/S0021889802000249Search in Google Scholar

[38] A. Rosenzweig, D. T. Cromer, The crystal structure of KAu(CN)2. Acta Crystallogr.1959, 12, 709.10.1107/S0365110X59002109Search in Google Scholar

[39] H. Klapper, T. Hahn, The application of eigensymmetries of face forms to X-ray diffraction intensities of crystals twinned by ‘reticular merohedry’. Acta Crystallogr. A2012, 68, 82.10.1107/S0108767311032454Search in Google Scholar PubMed

[40] G. M. Sheldrick, Crystal structure refinement with SHELXL. Acta Crystallogr. C2015, 71, 3.10.1107/S2053229614024218Search in Google Scholar PubMed PubMed Central

[41] R. Dinger, PhD thesis, Georg-August-Universität Göttingen, 1999.Search in Google Scholar

[42] APEX2 v2012/2, Bruker AXS Inst. Inc., Madison, WI, 2012.Search in Google Scholar

[43] G. M. Sheldrick, TWINABS v1.05 in Bruker APEX v2.1-0, Bruker AXS Inc., Madison, WI, 2005.Search in Google Scholar

[44] L. Krause, R. Herbst-Irmer, G. M. Sheldrick, D. Stalke, Comparison of silver and molybdenum microfocus X-ray sources for single-crystal structure determination. J. Appl. Crystallogr.2015, 48, 3.10.1107/S1600576714022985Search in Google Scholar PubMed PubMed Central

Supplemental Material:

The online version of this article (DOI: 10.1515/zkri-2016-1947) offers supplementary material, available to authorized users.

Received: 2016-3-21
Accepted: 2016-4-26
Published Online: 2016-5-31
Published in Print: 2016-10-1

©2016 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  2. Graphical Synopsis
  3. Preface
  4. Solution and refinement of twinned structures
  5. Obituary
  6. Theo Hahn (1928–2016)
  7. Unravelling the diffraction pattern of a twin. I. Fundamentals
  8. Detection of twinning in macromolecular crystallography
  9. Twinning in chemical crystallography – a practical guide
  10. Crystallographic computing system Jana2006: solution and refinement of twinned structures
  11. Pseudo-symmetry analysis to unravel the secrets of twins – a case study with four diverse examples
  12. Allotwinning and OD-structures – the example of malonamide
  13. Twinned CsLn2F7 compounds (Ln=Nd, Gd, Tb, Er, Yb): the role of a highly symmetrical cation lattice with an arrangement analogous to the Laves phase MgZn2
https://doi.org/10.1515/zkri-2016-1947
Keywords for this article
chemical crystallography; refinement; solution; twin

Articles in the same Issue

  1. Frontmatter
  2. Graphical Synopsis
  3. Preface
  4. Solution and refinement of twinned structures
  5. Obituary
  6. Theo Hahn (1928–2016)
  7. Unravelling the diffraction pattern of a twin. I. Fundamentals
  8. Detection of twinning in macromolecular crystallography
  9. Twinning in chemical crystallography – a practical guide
  10. Crystallographic computing system Jana2006: solution and refinement of twinned structures
  11. Pseudo-symmetry analysis to unravel the secrets of twins – a case study with four diverse examples
  12. Allotwinning and OD-structures – the example of malonamide
  13. Twinned CsLn2F7 compounds (Ln=Nd, Gd, Tb, Er, Yb): the role of a highly symmetrical cation lattice with an arrangement analogous to the Laves phase MgZn2
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