Volume 2 Chapter 7 Numeric Sub-menu *SIGFLAG

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*SPGNUMBER

Function

*SPGNUMBER is used to test for a specified space group number.

CSD Contents

Space group numbers correspond to those used in International Tables for Crystallography. They are listed in Appendix 7.

Graphics QUEST3D Procedure

Select *SPGNUMBER from the NUMERIC sub-menu and respond to the standard numeric prompts.

Basic QUEST Procedure

Ex.

T1 *SPGN .EQ. 52

This will register hits for all entries having space group number 52, ie. space groups Pnna, Pbnn, Pncn, Pnan, Pnnb, Pcnn.

Related Bit Screens

A number of bit screens can be used to search for various categories of space groups:

94 space group is completely defined
95 space group is partially defined
96 space group is not known
97 space group is centrosymmetric
98 space group is non-centrosymmetric
99 space group origin is at a centre of symmetry;
                                     atomic coordinates are present
100 space group origin is not at a centre of symmetry;
                                     atomic coordinates are present
101 space group is a Sohncke group
    ie. only symmetry elements are rotation and screw axes

Ex.

SCRE  97

This query screen registers hits for all entries having centrosymmetric space groups.

For screen 95 an aspect symbol replaces the full space group symbol.

Aspect symbols have numbers greater than 500 (see Appendix 7). Entries involving aspect symbols generally correspond to conference abstracts when the space group has not been fully determined.

Related Keywords

*SPACEGROUP

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Volume 2 Chapter 7 Numeric Sub-menu Standard Numeric Prompts.