Models: Phonons: get configuration using materialsproject API ?

[farhi]

An automatic search engine to look into:

• phonondb, fully open
• materialsproject API https://materialsproject.org/open which requires an 'API key'.

The idea is, from a chemical formula, to inquire if an existing configuration exists.

The materialsproject API key could be attached to a static account, e.g. ifit.sqw.phonons gmail account.Then, requests would use the gerenated certificate for all searches.

[farhi]

An probbly better alternative is to use COD, which supports mySQL queries:

• http://wiki.crystallography.net/howtoquerycod/

can for instance search for 'MgO' entries (given as elements seoarated with spaces) and get an HTML table:

• http://www.crystallography.net/cod/result.php?formula=Mg%20O

this can even be used with 'curl':

• curl http://www.crystallography.net/cod/result.php?formula=Mg%20O

which can then be filtered by searching e.g. lines with 'CIF' which then gives the COD entry numbers (after the first 'href' token). A dialogue could be displayed to choose the entry and attached spacegroup, or the browser could display the page for the user to get one of the CIF's.

Then get the 'cif' with e.g.:

• curl -s http://www.crystallography.net/cod/2002926.cif

[farhi]

Done with commit https://github.com/McStasMcXtrace/iFit/commit/2859dee0885d438a040329cd5d034795e6b83139

Usage:

• data = read_cif('Mg O')

displays a dialogue when multiple choices, and returns a structure with the cif content and cif2hkl information. Can also be processed with SpinW:

• plot(sw(data.file))

plot the 3D structure.

Requires to set the Proxy with:

ProxyHost='proxy.ill.fr'
ProxyPort=8888
java.lang.System.setProperty('http.proxyHost', ProxyHost);
com.mathworks.mlwidgets.html.HTMLPrefs.setUseProxy(true);
com.mathworks.mlwidgets.html.HTMLPrefs.setProxyHost(ProxyHost);
java.lang.System.setProperty('http.proxyPort', num2str(ProxyPort));
com.mathworks.mlwidgets.html.HTMLPrefs.setProxyPort(num2str(ProxyPort));