<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dcterms="http://purl.org/dc/terms/">
<rdf:Description rdf:about="https://archives.ihes.fr/document/P_85_68.pdf">
    <dcterms:title><![CDATA[What is a Crystal ?]]></dcterms:title>
    <dcterms:subject><![CDATA[CRISTAUX]]></dcterms:subject>
    <dcterms:subject><![CDATA[MATHEMATIQUES]]></dcterms:subject>
    <dcterms:subject><![CDATA[PAVAGE]]></dcterms:subject>
    <dcterms:subject><![CDATA[FONCTIONS]]></dcterms:subject>
    <dcterms:description><![CDATA[Abstract : An historical survey of our knowledge of crystal structure and of the mathematical problem of paving space with one or a few types of stones show that a crystal has not necessarily a translation lattice. The recently discovered crystals of alloys Al with 14% Mn have an ecosahedral symetry (incompatible qith translation lattice). Their electron micrographs show a structure similar to a Penrose tiling. It seems that long range order characterizing crystals can be obtained from projection of a thin slab of genuine crystal in higher dimension so that crystal physical properties can be described by quasi-periodic functions (as generalizing periodic ones) or may be almost periodic functions.]]></dcterms:description>
    <dcterms:creator><![CDATA[MICHEL]]></dcterms:creator>
    <dcterms:source><![CDATA[P/85/68]]></dcterms:source>
    <dcterms:publisher><![CDATA[IHES]]></dcterms:publisher>
    <dcterms:date><![CDATA[12/1985]]></dcterms:date>
    <dcterms:format><![CDATA[A4]]></dcterms:format>
    <dcterms:format><![CDATA[8 f.]]></dcterms:format>
    <dcterms:language><![CDATA[EN]]></dcterms:language>
    <dcterms:type><![CDATA[TEXTE]]></dcterms:type>
    <dcterms:type><![CDATA[PREPUBLICATION]]></dcterms:type>
    <dcterms:identifier><![CDATA[P_85_68.pdf]]></dcterms:identifier>
    <dcterms:coverage><![CDATA[1985]]></dcterms:coverage>
    <dcterms:provenance><![CDATA[IHES]]></dcterms:provenance>
    <dcterms:rightsHolder><![CDATA[IHES]]></dcterms:rightsHolder>
    <dcterms:rightsHolder><![CDATA[MICHEL]]></dcterms:rightsHolder>
</rdf:Description></rdf:RDF>