Crystallography Open Database

Information card for entry 9009746

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Coordinates	9009746.cif

Structure parameters

Formula	Mg2 O7 V2
Calculated formula	Mg2 O7 V2
Title of publication	Crystal structure of alpha-Mg2V2O7 from synchrotron X-ray powder diffraction and characterization by 51V MAS NMR spectroscopy Note: z-coordinate of V1 changed as directed by the author, Aug 2005.
Authors of publication	Nielsen, U. G.; Jakobsen, H. J.; Skibsted, J.; Norby, P.
Journal of publication	Dalton Transactions
Year of publication	2001
Journal volume	2001
Pages of publication	3214 - 3218
a	6.599 Å
b	8.406 Å
c	9.472 Å
α	90°
β	100.608°
γ	90°
Cell volume	516.443 Å³
Number of distinct elements	3
Space group number	14
Hermann-Mauguin space group symbol	P 1 21/c 1
Hall space group symbol	-P 2ybc
Has coordinates	Yes
Has disorder	No
Has F_obs	No

Version history

Revision	Date	Message	Files
291735 (current)	2024-05-06	Inserting Z values into entries in the 9 range that miss it.	9009746.cif
176465	2016-02-16	cif/ (antanas@kurmis) Replacing _[local]_cod_* tags with their equivalents from the COD CIF dictionary in multiple entries in range 9.	9009746.cif
85285	2013-05-05	cod/ (saulius@koala.ibt.lt) Removing outdated _amcsd_database_code data items from all series 9 CIFs.	9009746.cif
77877	2013-03-29	cod/ (saulius@koala.ibt.lt) Removing mineral names from those crystal structures that do not actually describe minerals (e.g. synthetic entries; data source: file COD-minerals.xlsx from my 2012-08-24 15:47 e-mail).	9009746.cif
77586	2013-03-28	cod/cif/ (saulius@koala.ibt.lt) Merging mineral data updates (_chemical_name_mineral, _chemical_name_common, structural formulae) sent to me by T.D. in his e-mail. The merge was done by the command: for i in split/*.cif do ( B=$(basename $i); C=$(echo $B\|awk '{print "/home/saulius/struct/cod/cif/"substr($0,1,1)"/"substr($0,2,2)"/"substr($0,4,2)"/"$0}'); ( set -x; cif_merge --over \ _chemical_name_mineral,_chemical_name_structure_type,_chemical_name_common,_chemical_name_systematic,_chemical_formula_structural,_chemical_formula_sum \ $C $i ) \ \| cif_filter --add-cif-header $C \ \| sponge $C ) done in the working copy of the following repository: URL: svn+ssh://pitonas.ibt.lt/home/xray/svn-repositories/xyz-extraction/contributions Repository Root: svn+ssh://pitonas.ibt.lt/home/xray/svn-repositories/xyz-extraction Repository UUID: 9acf3947-1f02-0410-ae2a-984b57ad209b Revision: 2625 Node Kind: directory Schedule: normal Last Changed Author: saulius Last Changed Rev: 2625 Last Changed Date: 2013-03-28 15:13:00 +0200 (Thu, 28 Mar 2013)	9009746.cif
35913	2012-02-28	cif/9/ Reorganising range 9 into a prefix-directory tree. Range 9 is the last range to be reorganised.	9009746.cif
1210	2010-06-10	cif/9/ Updating 13213 AMCSD CIFs, taking new data from the AMCSD database and adding the assigned AMCSD numbers.	9009746.cif
1071	2010-04-10	cif/9/ Updating COD entries from AMCSD, processed in the AMCSD-resynchronisation-2009.06.24/ directory. Entries are updated if they could be unambiguously mapped to a unique COD number by automatic search scripts in AMCSD-resynchronisation-2009.06.24/.	9009746.cif
966	2010-01-30	cif/ Adding _cod_database_code tags to all COD entries. Adding tag description to the cif_cod.dic dictionary so that COD entries can be validated.	9009746.cif
858	2009-11-18	cod/cif/ Changing all _chemical_formula_sum values, were necessary, to conform IUCr recommended syntax and sorting order. After this operation, it will be easier to search for structures using the _chemical_formula_sum values. Only those files and thos lines that really needed to be changed were changed; otehrwise the CIFs were not reformatted. The procedure was as follows: first, all files were passed through a 'cif_filter --parse-formula-sum' command, and the lines containing _cif_formula_sum matching tags were extracted. The extracted tags were "spliced" into the CIF files using the ./bin/{un,}grepciftag commands and awk to filter out old tags and add new tags in their place; the replacement was only done if the new tags contained "_cod_" tags ('grep -q _cod_ tmp-$$'), indicating that cif_filter has altered the formula, or the original file did not contain the _chemical_formula_sum tag ('! grep -q _chemical_formula_sum X'), indicating that cif_filter has guessed the chemical_formula_sum from the file (which should not have happened, actually). If the file was different, disregarding spaces, from the original one ('if ! diff -wb X tmp2-$$'), the original was replaced by the new file, to be committed to the repository. The full command for this step was: ( \ set -x; \ find ? -name \.cif \ \| xargs -n1 -iX \ sh -c 'cif_filter --parse-formula-sum X \ \| ./bin/grepciftag _chemical_formula_sum > tmp-$$; \ if grep -q _cod_ tmp-$$ \|\| ! grep -q _chemical_formula_sum X; \ then \ awk "/^#/,/_chemical_formula_sum/{print} /_chemical_formula_sum/{exit}" X \ \| ./bin/ungrepciftag _chemical_formula_sum > tmp2-$$; \ cat tmp-$$ >> tmp2-$$; \ awk "/_chemical_formula_sum/,/\$eof/" X \ \| ./bin/ungrepciftag _chemical_formula_sum >> tmp2-$$; \ if ! diff -wb X tmp2-$$; \ then \ mv -fv tmp2-$$ X; \ fi; \ fi; \ rm -f tmp-$$ tmp2-$$' \ ) >& sort-chemical-formulae-2009.11.16.log Next, the files were searched that differ from their originals only by the order of CIF tags: svn st \ \| awk '/^M/{print $NF}' \ \| sort \| xargs -n1 -iX \ bash -c 'if diff -q <(svn cat X\|sort) <(sort X) >& /dev/null; \ then echo X; \ fi' \ >& only-reordered.lst These files, after manual inspection ('cat only-reordered.lst \| xargs svn diff \| less'), were reverted to the originals: cat only-reordered.lst \| xargs svn revert Finally, a syntax check was performed using 'vcif': svn st \| awk '/^M/{print $NF}' \ \| sort \| xargs -n1 -iX \ sh -c 'echo -n X"\r"; vcif -l 2048 X \|\| { echo == X == ; echo X >&2; }' \ 2> vcif-check-2009.11.18.err A check on the whole COD archive showed the same files as recorded in vcif-check-2009.11.18.err: find ? -name \.cif \ \| sort \ \| xargs -n1 -iX \ sh -c 'echo -n X"\r"; \ vcif -l 2048 X \|\| { echo == X == ; echo X >&2; }' \ 2> vcif-all-check-`-date`.err diff vcif-check-2009.11.18.err vcif-all-check-2009.11.18.err Since no differences were detected in between vcif-check-2009.11.18.err and vcif-all-check-2009.11.18.err, the latter was deleted and is not committed. The check reveled two broken files, 2/2000267.cif and 2/2001000.cif; these were corrected manually. Afther this, one more 'vcif' check showed no syntax errors, and the changes are committed into the COD repository. 19798 files have modifications in this commit, according to svn st \| grep '^M' \| wc -l	9009746.cif
255	2008-03-10	Redepositing all AMCSD (9series) COD CIF files. This redeposition regenerates AMCSD (9 series) files, 10011 entries total, from the original source CIF file cifdata.cif found on the CD received from Armel. Most importantly, the truncated formulas seem to be corrected. The files are not folded, i.e. they have lines longer than 80 characters (conforming CIF 1.1 specification, but not CIF 1.0 specification), and are otherwise syntactically correct. Some missing coordinates were fixed manually, restoring them from the AMCSD site, and non-ASCII symbols were fixed automatically during filtering. After the redeposition, the cifs-with-errors.lst was regenerated using the following command: find -name \*.cif \ \| xargs -n1 -iI sh -c 'vcif -l 2048 I \|\| echo I' \ \| grep -vE 'CIF\|ERR' \ \| sort > cifs-with-errors.lst &	9009746.cif
19	2008-01-26	Changing all end-of-line codes from DOS style to UNIX style in all COD CIF files, for more convenient processing: In the cod/cif/ directory: ff \*.cif \| xargs perl -i -pe 's/\r\n/\n/'	9009746.cif
14	2008-01-14	Appending a header with SVN keywords, COD URL and copying policy to all COD CIF files.	9009746.cif
13	2008-01-13	Setting the svn:keywords property to "Author Date Revision URL Id" for all CIF files in the cod/cif directory.	9009746.cif
1	2007-11-30	Adding all .cif files from the COD, downloaded in a Cod.zip file on 2007.02.07 (and the same Cod.zip is downloadable today, on 2007.11.29)	9009746.cif