APPROXIMATE THEORIES OF THE RAMAN NON-COINCIDENCE EFFECT - A CRITICAL-EVALUATION IN THE CASE OF LIQUID ACETONE

Approximate theories of the Raman non-coincidence effect are examined on the basis of the results of Monte Carlo simulations. Special emphas is is laid upon the treatments of liquid structures incorporated in th ose theories. The concept of ''screening of two-body electrostatic int eractions'', which is involved in one theory of the Raman non-coincide nce effect, is shown to be inadequate in view of the calculated pair d istribution functions. However, the mean spherical approximation, on w hich another theory of the Raman non-coincidence effect is based, prop erly describes the local order in the liquid giving rise to that effec t, although ambiguities in estimating the effective hard sphere diamet er cannot be avoided.