Chemical shift prediction using quantum chemistry and density functional theory is a powerful tool for the characterization of organic compounds in both solution and solid state NMR. In solid state NMR, chemical shift prediction with CASTEP may be used as a guide for NMR assignment and structural characterization of crystal structures. However reference terms used in the calculation of ssNMR isotropic chemical shifts can have a profound effect on their accuracy. This is because the conversion of shielding constants to chemical shifts is typically performed using linear scaling within the molecule. This approach can bias the reference term yielding weighted agreement with experimental data. In addition linear scaling within a molecule can have compromised accuracy when there are only a few atoms in the molecule to generate the scaled term. Here we report the development of a generalized linear scaling term for use in the calculation of predicted <sup>13</sup>C ssNMR chemical shifts. Probability of the deviation between prediction from experiment and systematic error corollaries with solution NMR chemical shift prediction [1] will also be presented. This generalized reference term serves to improve the calculated precision of predicted isotropic ssNMR chemical shifts and expand the scope of the application.

Development of a generalized linear scaling reference term for accurate prediction of <sup>13</sup>C solid-state NMR isotropic chemical shifts

2019 Fall National Meeting

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Development of a generalized linear scaling reference term for accurate prediction of 13C solid-state NMR isotropic chemical shifts

Development of a generalized linear scaling reference term for accurate prediction of ¹³C solid-state NMR isotropic chemical shifts