Pair distribution function

Pair distribution function

The atomic pair distribution function (PDF) describes the density of interatomic distances in a material. Of special practical importance is the radial pair distribution function, which is independent of orientation. It is a major descriptor for the atomic structure of amorphic materials (glasses, polymers) and liquids. The radial PDF can be calculated directly from physical measurements like light scattering or x-ray powder diffraction.

In Statistical Mechanics the PDF is given by the expression:

g_{ab}(r) = frac{1}{N_{a} N_b}sumlimits_{i=1}^{N_a} sumlimits_{j=1}^{N_b} langle delta( vert mathbf{r}_{ij} vert -r) angle

See also

* Radial distribution function


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