alert Reported F000 Differs- CIF created with Olex2

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Raul007
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alert Reported F000 Differs- CIF created with Olex2

Post by Raul007 » 12 Aug 2019, 17:03

Hello,

I have a structure with some disorder and the check Cif has de following Alert:

PLAT068_ALERT_1_G Reported F000 Differs from Calcd (or Missing)... Please Check

This is the first time I see this alert so I am not sure whether it is import or not and why I am having it . I used Olex2 to prepare the CIF file.

Thank you very much!

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oleg
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Re: alert Reported F000 Differs- CIF created with Olex2

Post by oleg » 13 Aug 2019, 08:10

Hello,

here is the definition of the CIF entry:

https://www.iucr.org/__data/iucr/cifdic ... F_000.html

As you can see - it is not unique as may or may not include the dispersion terms. So on the first page of Platon/CheckCIF output you will see both - F000 for the term without dispersion contributions and F000' - with - the latter should be equal to the one reported by olex2.refine.

Cheers,
Oleg.

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Helge
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Re: alert Reported F000 Differs- CIF created with Olex2

Post by Helge » 13 Aug 2019, 09:04

Is it possible that you have a non-integer number of atoms in the unit cell? In other words, are there underoccupied atoms? Or perhaps two different molecules on top of each other? In my experience SHELXL rounds the F000 value to an integer number even if there is a non-integer number of atoms in the structure. In that case it is usually best to just replace the reported number with the one calculated by checkcif.

Raul007
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Re: alert Reported F000 Differs- CIF created with Olex2

Post by Raul007 » 13 Aug 2019, 10:12

Thank you Oleg and Helge for the comments and help.

Yes,I have a non-integer number of atoms in the unit cell because there is some substitutional disorder Br/Cl, so maybe that is why i get in the checkcif F000 1189.6 (calculated) 1190.0 (Reported)

Cheers,

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Helge
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Re: alert Reported F000 Differs- CIF created with Olex2

Post by Helge » 15 Aug 2019, 15:16

Raul007 wrote:
13 Aug 2019, 10:12
Yes,I have a non-integer number of atoms in the unit cell because there is some substitutional disorder Br/Cl, so maybe that is why i get in the checkcif F000 1189.6 (calculated) 1190.0 (Reported)
Indeed. In this case just write the calculated F(000) into your cif.

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