Physical Review A
A simple formulation i presented for the analysis of nuclear quadrupole spectra in biaxial liquid crystals based on orientational order parameters. The analysis contains no tilt angle or other model-dependent parameters not directly measured in NMR experiments. The observability and effect of various order parameters on the asymmetry of the electric field gradient η is discussed. It is shown that η is insensitive to rotational freeze-out of the variety expected to be observed in some biaxial phases. Nuclear quadrupole resonance experiments are described which are expected to yield rotational freeze-out parameters.
Allender, David W. and Doane, J. William (1978). Biaxial Order Parameters in Liquid-Crystals - Their Meaning and Determination With Nuclear-Quadrupole Resonance. Physical Review A 17(3), 1177-1180. doi: 10.1103/PhysRevA.17.1177 Retrieved from https://digitalcommons.kent.edu/phypubs/18