Author/Authors :
Zheng، نويسنده , , Anmin and Yang، نويسنده , , Minghui and Yue، نويسنده , , Yong and Ye، نويسنده , , Chaohui and Deng، نويسنده , , Feng، نويسنده ,
Abstract :
Our-own-N-layered integrated molecular orbital + molecular mechanics (ONIOM) method has been applied to calculate 13C chemical shift shielding tensor of the carboxyl carbon in three amino acid crystals. The calculated shielding tensors are in good agreement with the experimental values. The root mean square (RMS) has dramatically decreased to 5.9 ppm compared to that (35.5 ppm) previously reported in reference. The present investigation has proved that the surrounding lattice environment plays an important role in the calculation of chemical shift tensors of amino acids.
