QMGreensite_merged

which is indicative of a very small net alignment. The dependence of
DIS on B^20 can be used to separate DIS from the scalar coupling
constantJIS.
The effects of partial alignment of small molecules have been
observed for the chemical shift, dipole–dipole, and quadrupole nuclear
spin Hamiltonians ( 25 ). Alignment has been obtained using electric
fields, magnetic fields, thermotropic liquid crystals, and lyotropic liquid
crystals. Applications to proteins and other biological macromolecules,
including the use of liquid crystalline and other media to obtain larger
degrees of alignment ( 23 ), are discussed in Chapter 7.

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112 CHAPTER 2 THEORETICALDESCRIPTION OFNMR SPECTROSCOPY