extract_symmetry_info: Information on a specific space group

In cry: Statistics for Structural Crystallography

Information on a specific space group

Description

Returns human-readable information on a specific input space group.

Usage

extract_symmetry_info(SG)

Arguments

SG	A character string. The extended Hermann-Mauguin symbol (e.g. 'P 1 1 21')

Details

Crystallographic symmetry is fundamental in crystallography. It affects the way atoms are arranged in a unit cell, the pattern of reflections in reciprocal space and many other common occurrences in crystallography. This function returns a named list with human-readable character strings which detail key symmetry information.

Value

infostring A named list with fields corresponding to those in the CCP4 symmetry library. The fields' name are:

• NUMBER standard spacegroup number

• BASISOP change of basis operator

• CCP4 CCP4 spacegroup number e.g. 1003 (0 if not a CCP4 group)

• HALL Hall symbol

• xHM extended Hermann Mauguin symbol

• OLD CCP4 spacegroup name (blank if not a CCP4 group)

• LAUE Laue group symbol

• PATT Patterson group symbol

• PGRP Point group symbol

• HKLASU reciprocal space asymmetric unit (with respect to standard setting)

• MAPASU_CCP4 CCP4 real space asymmetric unit (with respect to standard setting. Negative ranges if not a CCP4 group)

• MAPASU_ZERO origin based real space asymmetric unit (with respect to current setting)

• MAPASU_NONZ non-origin based real space asymmetric uni (with respect to current setting)

• CHESHIRE Cheshire cell (with respect to standard setting)

• SYMOP list of primitive symmetry operators

• CENOP list of centering operators

Examples

# This is the full information for space group number 19, P 21 21 21
SG <- translate_SG(19)
ltmp <- extract_symmetry_info(SG)
ltmp

cry documentation built on Oct. 10, 2022, 9:06 a.m.