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Electron density calculator for the 3D-cubic lattics Pm-3m (221), Fm-3m (225) and Im-3m (229)**
This Javascript calculates the 3D electron density distribution rho(r) of a cubic lattices of space group 221, 225 and 229 from diffraction data.
Enter the number of peaks (note: the hkl-reflections are listed for 221/225/229 and some are doublets!) and the value of the cubic lattice spacing (a=b=c or length of the unit cell).
Enter the peak intensities I(q) or peak amplitudes F(q) and their signs of the scattering amplitudes (+ or -). Select the space group and the corrections already applied to the input data: 'none' means no corrections,
LC means Lorentz correction (multiplied by q*q) and MC means multiplicity correction (divided by the multiplicities) have already been applied. F(q) have to be entered both LC and MC corrected.
Optionally also I(0) or F(0) as a constant offset can be entered. Enter the value for rz (rz = 0 means the 1/0/0 = 0/1/0 = 0/0/1 hkl-plane and rz = a/2 means the slice pararallel to the 1/0/0 plane through
the center of the unit cell) and the number of unit cells (n x n).
Note that for the cubic spacegroups 221/225/229 the rx-ry, rx-rz and ry-rz planes are symmetry equivalent. For the calculation/plotting of
5 equidistant slices in the z-direction click

here.
For 2*Nr points the electron density rho(r) - multiplied by the scaling factor f (if f = 0 then the electron density is divided by the volume of the unit cell) - at the z-position = rz for n x n unit cells will be calculated
with the origin of the unit cell located at rx=ry=0.
The color-scaling for the e-density data can be adjusted by entering the zmin and zmax levels. In case zmax <= zmin an autoscaling is done. The first (upper) 3D-Plot however is always autoscaled.
If the calculation takes too long (on a slow computer) decrease the number of points Nr.
The values are listed/plotted in rho(r) vs rx, ry in arbitrary units and can be copied and pasted from the window into any text-file for further processing and graphical displaying.