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...reduced

The reduced operation is derived from a given operation by removing any intrinsic screw or glide translation. Hence, if the latter is zero, reduction does not change the operation.

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...normalizer

The term `Euclidean normalizer' is generally used in relation to subgroups of the group E of all congruences (`Euclidean mappings'), cf. International Tables for Crystallography (1987). In the sense used here (relating not to a subgroup but to a single group element W), the normalizer is also called the centralizer of W, cf. Ledermann (1973).

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Copyright © 1989, 1998 International Union of Crystallography