Reporting and evaluating absolute-structure and absolute-configuration determinations
نویسندگان
چکیده
Detailed practical and numerical information is provided for undertaking and evaluating absolute-structure and absolute-con®guration determinations. The interpretation of numerical values of x, the Flack [Acta Cryst. (1983), A39, 876± 881] parameter, and its standard uncertainty u are explained in terms of the inversion-distinguishing power. Moreover, the conditions to obtain reliable values of x(u) are detailed. Further explanatory material is provided on the use of right-handed axes, valid intensity data, the application to macromolecular structures, the dangers of polar-dispersion errors, Euclidean normalizers of space groups, the detection and reporting of molecular symmetry, enantiopurity and optical activity in solution. New CIF data names are introduced.
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