Shown below is the projected electron density using the experimental
data at l=.01 for different scaling
factors. The scaling factor doesn't seem to have much effect on the results over a reasonable
range. The extra oxygens that I had considered in the previous results appear to have been
due to the scaling, however.
Scale = .40
Below is the same result as above, except I have made the projected
density slightly transparent
so that the bulk copper can be seen as represented by the smaller green spheres. It occured to us
that the extra features (circled in yellow) in the density could be additional reconstructed copper
atoms from further into the bulk. These features could also be caused by improper scaling of the
ulk amplitudes although the fact that they appear regardless of the scaling makes them seem
Here is a perspective view showing some of the bulk atoms.
An r-factor comparison of the model with the data as a function of just
the scale factor gave
Scale=.365 as the optimal. Our algorithm gave virtually the same result
as scale=.4 when run with this scale.
Here are a couple more results with different scale factors.