Hi Pavel
AFAIK it's not in the literature, in fact I wasn't even aware it was
in phenix, but that's probably only because we don't use phenix
(sorry! - being commercial we would have to pay for it!). The problem
is always where you put little tidbits like this, unless it's part of
a much bigger piece of work.
Cheers
-- Ian
On Mon, Apr 19, 2010 at 7:35 PM, Pavel Afonine <[log in to unmask]> wrote:
> Hi Ian,
>
>> ... or you could just use the RMSD of the difference map (i.e. that
>> using 2(mFo-DFc) coefficients for acentric reflns), which is a
>> reasonable approximation of the uncertainty provided most of the
>> structure is accounted for, as the uncertainty of the Fourier map
>> (i.e. that using 2mFo-DFc for acentrics). Note that for this to work
>> you must use the correct 'minimally biased' coefficients, i.e.
>> 2(mFo-DFc) for acentric reflns, and (mFo-DFc) for centrics; I suspect
>> some programs are still not doing this correctly.
>
> thanks for shedding some light on this subject! I coded this way of map
> calculation in phenix.refine without actually understanding why it has to be
> this way. Did anybody discuss this in the literature (or it's too obvious to
> be worth of discussion -:) )?
>
> Pavel.
>
>
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