I would say so yes, but Garib is the expert on this - I'm only repeating
what he told me!

Cheers

-- Ian


On 15 March 2018 at 14:41, Eleanor Dodson <eleanor.dod...@york.ac.uk> wrote:

> So if I calculate "structure factors" from a map do I just use the map as
> is with the negative values included ?
>
> Eleanor
>
> On 15 March 2018 at 14:37, Ian Tickle <ianj...@gmail.com> wrote:
>
>>
>> Hi Eleanor
>>
>> Electron scattering factors can be negative for negative ions,
>> particularly at low d*.  For a low-resolution map it means that the
>> electric potential is the opposite sign to what you expected.  It's why you
>> often don't see ASP & GLU side-chains in low resolution EM maps.
>>
>> Cheers
>>
>> -- Ian
>>
>> On 15 March 2018 at 14:17, Eleanor Dodson <0000176a9d5ebad7-dmarc-reques
>> t...@jiscmail.ac.uk> wrote:
>>
>>> I am pig-ignorant about these ,, but this example has negative values as
>>> well as positive..
>>>
>>> What does this mean? I thought a well phased map would be pretty well
>>> all positive..
>>>
>>>  Eleanor
>>>
>>
>>
>

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