Crystallography Open Database

Information card for entry 5910078

5910077 << 5910078 >> 5910079

Preview

Coordinates	5910078.cif

Structure parameters

Chemical name	mgZn2
Formula	Mg Zn2
Calculated formula	Mg Zn2
a	5.15 Å
b	5.15 Å
c	8.48 Å
α	90°
β	90°
γ	120°
Cell volume	194.778 Å³
Number of distinct elements	2
Space group number	194
Hermann-Mauguin space group symbol	P 63/m m c
Hall space group symbol	-P 6c 2c
Has coordinates	Yes
Has disorder	No
Has F_obs	No

Version history

Revision	Date	Message	Files
177123 (current)	2016-03-02	cif/5/91/ Adding standard COD SVN header to CIF entries 591*.	5910078.cif
35911	2012-02-28	cif/ Reorganising ranges 1, 3, 5, 6 and 8 into a prefix-directory tree.	5910078.cif
20965	2011-06-21	cif/5/ A bug report was received from Stefaan Cottenier: ------------------------------------------------------------------------------ From: Stefaan Cottenier <Stefaan.Cottenier@xyzt.be> To: Saulius Grazulis <grazulis@xyz.lt> Date: 2011-06-21 14:49 /.../ Let me take this occasion to mention something which I noticed yesterday, while depositing this and other files: is the MgZn2 cif file which is in COD a correct one? MgZn2 is the prototype for the YTc2 and ZrTc2 structures which I deposited yesterday. Yet, according to the cif in COD, it has only 2 wyckoff positions, while it should have 3 (6h seems to be missing). This is confirmed by http://cst-www.nrl.navy.mil/lattice/struk/c14.html, which is quoted as the source where this COD cif file was derived from. ------------------------------------------------------------------------------ The checks using 'cif_cell_contents -Z=4' filter indictated composition derived from the 5910078.cif revision r1090 that was not consistent with the chemical formula provided in the file. In addition, two the Mg and the two Zn atoms were on the crystallographically equivalent positions. Comparison with the YTc2 structure and with the http://cst-www.nrl.navy.mil/lattice/struk.xmol/c14.pos file showed that most likely the wrong coordinate lines were picked. Following this bug report, the following changes in the entry have been made: a) fractional coordinates were picked from http://cst-www.nrl.navy.mil/lattice/struk.xmol/c14.pos that are equivalent to positions reported in the YTc2 structure (COD file 1501465.cif); b) Wyckoff letters and multiplicities were taken from the 1501465.cif file, and checked against the International Tables (5th ed., 2002, vol. A, p. 601); c) _cell_formula_units_Z were set to 4, as in the YTc2 structure (1501465.cif), and consistent with the provided _chemical_formula_sum.	5910078.cif
1090	2010-04-14	cif/5/ Adding new files uploaded by Girish Upreti, mostly historic inorganic structures from Wyckoff, R. W. G. books (keyed in manually?).	5910078.cif