__Data definition__

*i(Q)* data are defined according
to the standard ISIS histogram data convention: each (*x*,*y*) pair
represents the top left corner of a histogram. The data can be converted to
ordinary data points by replacing each *x*-value *x _{i}* by
0.5*(

Real-space data (*T(r)* or *D(r)*)
are given as conventional (*x*,*y*) data points.