Structure determination from powder data: Mogul and CASTEP

A.J. Florence, J. Bardin, Blair Johnston, N. Shankland, K. Shankland

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

When solving the crystal structure of complex molecules from powder data, accurately locating the global minimum can be challenging, particularly where the number of internal degrees of freedom is large. The program Mogul provides a convenient means to access typical torsion angle ranges for fragments related to the molecule of interest. The impact that the application of modal torsion angle constraints has on the structure determination process of two structure solution attempts using DASH is presented. Once solved, accurate refinement of a molecular structure against powder data can also present challenges. Geometry optimisation using density functional theory in CASTEP is shown to be an effective means to locate hydrogen atom positions reliably and return a more accurate description of molecular conformation and intermolecular interactions than global optimisation and Rietveld refinement alone.
LanguageEnglish
Pages215-220
Number of pages5
JournalZeitschrift fur Kristallografie
Volume30
DOIs
Publication statusPublished - 2009

Fingerprint

Torsional stress
Powders
torsion
Molecules
Rietveld refinement
optimization
Global optimization
Molecular structure
Density functional theory
Conformations
molecules
Hydrogen
hydrogen atoms
molecular structure
degrees of freedom
Crystal structure
fragments
density functional theory
Atoms
crystal structure

Keywords

  • structure determination
  • powder data
  • simulated annealing
  • torsion angle
  • geometry optimisation

Cite this

Florence, A.J. ; Bardin, J. ; Johnston, Blair ; Shankland, N. ; Shankland, K. / Structure determination from powder data: Mogul and CASTEP. In: Zeitschrift fur Kristallografie. 2009 ; Vol. 30. pp. 215-220.
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Structure determination from powder data: Mogul and CASTEP. / Florence, A.J.; Bardin, J.; Johnston, Blair; Shankland, N.; Shankland, K.

In: Zeitschrift fur Kristallografie, Vol. 30, 2009, p. 215-220.

Research output: Contribution to journalArticle

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T1 - Structure determination from powder data: Mogul and CASTEP

AU - Florence, A.J.

AU - Bardin, J.

AU - Johnston, Blair

AU - Shankland, N.

AU - Shankland, K.

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KW - structure determination

KW - powder data

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KW - torsion angle

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