That is, from chair to boat, each exo-TCD configurations are optimized (i.e., relaxed) before further property calculations are performed. The 1 H-NMR and 13 C-NMR isotropic shielding values of the exo-TCD stereoisomer pair are calculated using the gauge invariant atomic orbital (GIAO) method and the DFT-based B3LYP/cc-pVTZ and B3PW91/cc-pVTZ models, respectively. The NMR chemical shifts of exo-TCD isomers were compared with the internal reference standard, tetramethylsilane (δH(TMS)=31.8821 ppm and δC(TMS)=182.4656 ppm).