Tables for
Volume G
Definition and exchange of crystallographic data
Edited by S. R. Hall and B. McMahon

International Tables for Crystallography (2006). Vol. G. ch. 3.4, p. 133

Section Data collection

G. Madariagaa*

aDepartamento de Física de la Materia Condensada, Facultad de Ciencia y Tecnología, Universidad del País Vasco, Apartado 644, 48080 Bilbao, Spain
Correspondence e-mail: Data collection

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The categories describing data collection are as follows:

DIFFRN group

Categories marked with ¶ are already defined in the core CIF dictionary.

New data items in these categories are as follows:

(a) DIFFRN_REFLN [Scheme scheme7]

(b) DIFFRN_REFLNS [Scheme scheme8]

(c) DIFFRN_STANDARD_REFLN [Scheme scheme9]

The data items in these categories are straightforward extensions of the core CIF dictionary definitions to the indexing of diffraction intensities by higher-dimensional components. The _diffrn_refln_index_m_* items are the additional Miller indices [m_i] indexing the modulation wave vectors [{\bf q}_i] when the diffraction wave vector is written as [{\bf H}=h {\bf a}^{*}+k {\bf b}^{*}+ l{\bf c}^{*}+ \textstyle\sum_i m_{i} {\bf q}_{i}].

The upper limit of 8 was chosen arbitrarily to limit the number of data items defined in the msCIF dictionary.

_diffrn_reflns_limit_index_m_* items provide independent checks on the range of values recorded for each of the additional Miller indices [m_i]. _diffrn_standard_refln_index_m_* items allow the higher-dimensional Miller indices of standard reflections to be recorded.

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