I suppose I should have expected this, but I still was led astray.. Ir atom - strong anomalous signal.. Good peak in anom diff fourier phased from protein.
So I add it to the model with occ = 1.00 and refine.. The B factor is very high and it seems clear that the occupancy should be <<1.0 And one side effect is that now the anomalous difference fourier has a large HOLE where I have placed the Ir. Hmmm. Eleanor
