We report a deuterium nuclear magnetic resonance (NMR) investigation of octa-O-decanoylthio-beta,beta-trehalose (TTH-10) in the solid state. For the interpretation of deuterium NMR line shapes and spin-lattice relaxation rates, a two-site exchange model was invoked. The motional amplitude for the C-D vector in TTH-10 molecule was estimated to 72 degrees, while the relative populations of the two sites were assumed to be temperature dependent. From the longitudinal deuterium relaxation rates, correlation times for the dynamic process were derived. We found these to be approximately 50 ns at 20 degrees C and 30 ns at 90 degrees C. In addition to NMR experiments, molecular dynamics (MD) computer simulations of octa-O-acetylthio-beta,beta-trehalose (TTH-2) and an oxygen analogue, octa-O-acetyl-beta,beta-trehalose (TH-2), were performed. The analysis of the two torsion angles relevant for the glycosidic linkage indicates that the conformations of the TTH-2 molecule essentially correspond to two states. This observation gives strong support for our assumption about the two-site exchange model used for interpretation of deuterium solid-state experiments.