J. Appl. Cryst. (2002), 35, 168-174. Â Â [ 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 |Fc… Read the rest
Acta Cryst. (2000), B56, 747-749. Â Â [ 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
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
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
Acta Cryst. (1979), A35, 698-699. Â Â [ 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
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