الفهرس 
Aperiodic CrystalsOnly 14 pages are availabe for public view
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Abstract
Supramolecular or self-assembled materials often result from a subtle balance of
weak intermolecular interactions yielding to a large variety of ordered and
disordered phases with many different physical, chemical or mechanical
properties. Alkane urea inclusion compounds (UIC) are molecular composite
structures where a ”host” framework of urea molecules accommodates ”guest”
alkane molecules as long chains loosely held in a honey-comb like hexagonal
network of adjacent channels. Most of the alkane-UICs are incommensurate or
aperiodic, which means that the ratio of the host and guest periodicities is not a
rational number M/N. As a consequence, very different types of short and long
range ordering, as well as different phase transitions take place in these alkane-UICs just by changing the length of the alkane molecules. Even if these
compounds are aperiodic by construction, periodicity can be recovered in
superspaces of dimension greater than 3 and where full power of Fourier
analysis can be used for crystallographic investigation.