Pair-distance distribution function PDDF

For a particle of an arbitrary shape having a scattering density difference of Ap(r), the pair-distance distribution function (PDDF) is given by... 

Figure 2.6 (a) The X-ray scattered intensities, l q), of the 5 wt% CioCi/liquid paraffin in absolute unit at different temperatures (50, 55, and 60°C), and (b) the pair-distance distribution functions (PDDFs), p(r), extracted from these scattering curves with the GIFT method. Solid and broken lines in (a) represent GIFT fit and the calculated (total) form factor for n particles... 

Figure 10.5 The pair-distance distribution functions (PDDFs), p(r), of the EG /SinCsEOss, systems (a) and those of the EG /SinCjEOs, s systems (b) at 60 C. The concentration of SinCjEO in EG, is fixed to 2 wt%.

It is conventional to express tlie stmctiiral infomiation in temis of a pair distance distribution function, or PDDF [5], which is defined by p(r) = p-P(r). Using this, equation (Bl.8.10 becomes... 

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