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Re: Question: representation of uncertainties in scientific notation

  • Subject: Re: Question: representation of uncertainties in scientific notation
  • From: Nick Spadaccini <nick@xxxxxxxxxxxxx>
  • Date: Fri, 2 Aug 2002 02:27:46 +0100 (BST)
On Thu, 1 Aug 2002, Brian H. Toby wrote:

>    Does anyone know how CIF handles numbers with "esd's" when they are
> in exponential notation, (at least for DLL 1.x, where numbers may be
> reported as -12.345(2) if the esd flag is true.)
> 
>    My understanding is the conventional crystallographic notation for a
> number in exponential notation is 
> 
> 	-1.2345(2) x 10^1
> 
> but my reading of section 59 in
> http://www.iucr.org/iucr-top/cif/developers/spec/cifsyntax.html 
> is that CIF uses 
> 
> 	-1.2345e1(2)
> 
> I just want to check that -1.2345(2)e1 is not valid and has never been
> intended to valid in CIF.

I would guess that -1.2345(2)e1 looks more natural, but -1.2345e1(2) would 
be equally valid unless there is a case where you may need to record a 
standard uncertainty in the exponent. Unlikely.


cheers

Nick

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