General properties dynamic structure factor

Distinct characters of the static structure enter the specification of this more complex motion. Same as for librational oscillations, the symmetry of tumbling reorientations proceeds from both the symmetry of the intermolecular torques and the symmetry of the molecules themselves through the values of their distinct molecular moments of inertia. The most prominent role of inertial factors, and more recently that of torques too, have been made especially clear by W.A. Steele (1). Apart from these molecular and local factors, collective properties of the liquid enter the dynamics through the rate of reorientation. This rate itself is a combination of two factors, generally undistin-guishable in the observed mean value these are the velocity of the angular rotation and the rate of occurence of elementary rotations. Hereafter in section V we will come back to experimental approaches specifying the rate of occurence dependence upon the liquid equation of state (i.e. its temperature and density dependence). ... 

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