[phenixbb] anomalous difference map

[CPMAS Chen]

Hi, All

Please correct me if I am wrong on this.

Suppose I have a peak in the anomalous difference map, I should place Br
(in my case) at the peak position, while the other part of the molecule in
the peak of the difference map. Should I always expect to see the overlaps
of these two peaks? at some positions, I see they are apart by 1~2A.


Thanks!

Charles

On Wed, Sep 10, 2014 at 9:10 AM, CPMAS Chen <cpmasmit at gmail.com> wrote:

> Thanks, Nat.
>
> If this is noise, why the anomalous or LLG peaks could be as high as 5 ~ 6
> sigma?
>
> Charles
>
> On Tue, Sep 9, 2014 at 5:58 PM, Nathaniel Echols <nechols at lbl.gov> wrote:
>
>> On Tue, Sep 9, 2014 at 8:40 AM, CPMAS Chen <cpmasmit at gmail.com> wrote:
>>
>>> Is it possible that I have anomalous and LLG peak, but I have no
>>> difference density peak? In this case, is that because the model I have is
>>> not good enough or the diffraction data at this site of the model is
>>> missing?
>>>
>>
>> You should at a minimum see > 1sigma density in the 2mFo-DFc map, and if
>> the site is unmodeled (or modeled as a water) you should see an mFo-DFc
>> peak as well.  If neither of these applies, the anomalous and LLG peaks are
>> probably just noise.
>>
>> -Nat
>>
>
>
>
> --
>
> ***************************************************
>
> Charles Chen
>
> Research Associate
>
> University of Pittsburgh School of Medicine
>
> Department of Anesthesiology
>
> ******************************************************
>
>


-- 

***************************************************

Charles Chen

Research Associate

University of Pittsburgh School of Medicine

Department of Anesthesiology

******************************************************
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