Powder dictionary (pdCIF) version 1.0.1
Description of the background treatment mechanism used to fit the data set. For refinements where the background is computed as a function that is fitted to minimize the difference between the observed and calculated patterns, it is recommended that in addition to a description of the function (e.g. Chebychev polynomial), the actual equation(s) used are included in TeX, or a programming language such as Fortran or C. Include also the values used for the coefficients used in the background function with their s.u.'s. The background values for each data point computed from the function should be specified in _pd_proc_intensity_bkg_calc. If background correction is performed using extrapolation from a set of points at fixed locations, these points should be defined using _pd_proc_intensity_bkg_fix, and _pd_proc_ls_background_function should indicate the extrapolation method (linear extrapolation, spline etc.). _pd_proc_ls_background_function should also indicate how the points were determined (automatically, by visual estimation etc.) and whether the values were refined to improve the agreement. The extrapolated background intensity value for each data point should be specified in _pd_proc_intensity_bkg_calc.