Crystallography has traditionally been studied by diffraction methods involving X ray or neutron radiation. These methods have some limitations, from requiring the substance under study to form single crystals to the limited ability of X rays to locate hydrogen atoms. While neutron radiation can characterize hydrogens, it is expensive, not readily available and has its own particular limits on resolution. It this dissertation, it is demonstrated that NMR is extraordinarily sensitive to atomic positions, with variations of mere tens of femtometers creating statistically distinguishable chemical shift changes. To date, no other means of measurement can detect structural changes at this scale. This thesis presents a NMR based refinement technique that refines existing X ray structures to an unprecedented resolution. The refinement uses computational methods to make theoretical models then fits these models to the experimental data. This refinement process can also be modified to generate positional uncertainties known as the anisotropic displacement parameters, or ADPs, to accompany the refined structure. This creation of ADPs fulfills requirements set by the international union of crystallography that all deposited crystal structures contain ADPs.
College and Department
Physical and Mathematical Sciences; Chemistry and Biochemistry
BYU ScholarsArchive Citation
Wang, Luther, "Computationally Assisted NMR Crystallography: A Path to Unusually High-Resolution Crystal Structures" (2022). Theses and Dissertations. 9397.
NMR, DFT, Crystallography, Structure Refinement