Measurements of P2 cos 0 Based on Microscopic Anisotropies

In this section we group techniques that sense the anisotropy in various properties of individual molecules as opposed to those discussed above, which sense bulk anisotropies. It is impossible to measure the anisotropy of a single molecule in a nematic phase rather, these techniques measure the statistical average (both temporal and spatial) of the molecular anisotropy. The averaging process results in the measured anisotropy being proportional to P2 (cos ) for most of these techniques. For the technique based on Raman scattering measurements, the anisotropy is related to both P2 (cos ) and P4(cos 0) . 

Having three moments P , P2 and P of the orientational distribution function allows us to evaluate (cos 6) (See Sec. 2). In the next section we present NMR, optical and magnetic anisotropy, and Raman measurements of P2 (cos ) , Raman measurements of P4 (cos 0 ) , and representative plots of (cos 0). 

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