> What about the bogey of Fourier truncation ripples--I have heard many have > been fooled by the into thinking they were seeing orbitals. How does one > tell the difference?
Indeed, there are such dangers. Hints are here: On the possibility of observation of valence electron density for individual bonds in proteins in conventional difference maps. (2004). Acta Cryst., D60, 260-274. Have a look at Figure 4. Then compare with Figure 1 here: J. Biol. Chem. (1999) 274, 20753-29755. Bottom line is: be careful with unbalanced Fourier syntheses, balanced ones may be a safer option. Pavel
