  This paper deals with the comparative use of the chemical shift surfaces to
simulate experimental 13C CPMAS data on amorphous solid state disaccharides,
paying particular attention to &#61537;-1-1 linkage of trehalose, to
&#61538;-1,4 linkage between pyranose rings (lactose) and to linkage implying a
furanose ring (sucrose). The combination of molecular mechanics with DFT/GIAO
ab-initio methods provides reliable structural information on the
conformational distribution in the glass. The results are interpreted in terms
of an enhanced flexibility that trehalose experiences in amorphous solid state
compared to the other sugars. An attempt to relate this property to the balance
between intra- and inter-molecular hydrogen bonding network in the glass is
presented.
