Apr 222004
 
CRYSTALS Enhancements: Refinement of Atoms Continuously Disordered Along a Line, on a Ring or on the Surface of a Sphere (L. Schröder, D. J. Watkin, A. Cousson, R. I. Cooper and W. Paulus)

J. Appl. Cryst. (2004), 37, 545-550.    [ doi:10.1107/S0021889804009847 ]

The program CRYSTALS [Betteridge, Carruthers, Cooper, Prout & Watkin (2003). J. Appl. Cryst. 36, 1487] has been extended to include an option for the refinement of a continuous electron density distribution lying along a line, a ring or on the surface of a sphere. … Read the rest

Dec 012003
 

J. Appl. Cryst. (2003), 36, 1487.    [ doi:10.1107/S0021889803021800 ]

CRYSTALS version 12 contains a modern crystallographic user interface, and novel strategies that incorporate chemical knowledge and crystallographic guidance into the crystal structure analysis software.

Electronic reprints

Publisher’s copy

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Apr 012002
 

J. Appl. Cryst. (2002), 35, 168-174.    [ doi:10.1107/S0021889802000249 ]

Although non-merohedrally twinned crystal structures can normally be solved without difficulty, problems usually arise during refinement. Careful analysis of poorly fitting data reveals that they belong predominantly to certain distinct zones in which |Fo|2 is systematically larger than |FcRead the rest

Oct 172000
 

Acta Cryst. (2000), B56, 747-749.    [ doi:10.1107/S0108768100008466 ]

The reporting of Uequiv and its standard uncertainty has a chequered history. In spite of the recommendation of the IUCr Commission on Journals that authors use the definition of Uequiv of their own choice, possibly without standard uncertainties, there still seems to be … Read the rest

Aug 141999
 
XVIII International Congress and General Assembly of the International Union of Crystallography

The 18th International Union of Crystallography Congress and General Assembly was held in Glasgow in August 1999. Those attending from the Chemical Crystallography Laboratory in Oxford were:
Professor Keith Prout, Dr David Watkin, Dr Theirry Maris, Richard Cooper, Clare Keats and Ibrahim Tahir.… Read the rest

Jul 011994
 

Acta Cryst.  (1994), A50, 411-437.    [ doi:10.1107/S0108767393012784 ]

Each year, many single-crystal structure analyses are reported that show evidence of over- or under-refinement. Often, the refinement strategies have been naive or over-complex and alternative strategies might have been more effective. The many descriptions of crystallographic and numerical techniques suitable for assisting with the control … Read the rest

Jul 171979
 

Acta Cryst. (1979), A35, 698-699.    [ doi:10.1107/S0567739479001613 ]

The truncated Chebyshev polynomial provides a reliable scheme for the automatic determination of empirical weights for least-squares structure refinement when the errors are a function of |Fo|.… Read the rest

Mar 131972
 

J. Appl. Cryst.  (1972), 5, 250.    [ doi:10.1107/S0021889872099996 ]

The principle of this apparatus is not new (Hope, 1971), but it is reported because of interest shown in its simplicity by visitors to this laboratory. Small samples of the solute are heated in a saturated solution in a poor solvent, and convection and diffusion … Read the rest