Hi James!
Thank you very much for the gnuplot-ish version of ${CLIBD}/atomsf.lib!! It
works very nice and is very useful for education!
As I understand, the form factor is the Fourier transform of electron charge
density. It is plotted as f(electrons) vs sin(tetta)/lambda and is approximated
as 5 Gaussian (Cromer and Mann) in REFMAC. And you made reverse Fourier
transform of the approximation and plotted the electron density distribution in
the real space.
So, can I ask, what unit is x? Is it angstrom?
And what is Y? is it e/A3 (electron density)?
I found, that at Bf=20, density profiles look almost the same for ions and
atoms (Mg2+ and Mg, Cl- and Cl). Does that means, there is no sense to specify
atomic charge in refmac refinement? It looks a bit strange, because the numbers
of electrons are different. Or decreasing in number of electrons is compensated
with significant decrease in atom size (that can have the same effect as Bf
lowering)? With Bf=0 the difference in curves is significant.
With best regards,
Ivan Shabalin
