Discussion List Archives

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Draft changes to Core data names for multiplicity etc.

On 16.05.2012 12:32, Brian McMahon wrote:

> The expression for a structure factor

   I think this should be
   "The expression for the structure-factor amplitude"

> This may contain dispersion contributions

   I object to the use of the term "dispersion".  Current usage favours 
"resonant-scattering" although some use "anomalous-scattering" despite 
there being nothing anomalous about the phenomenon.

> F(000) = [ (sum f~r~)^2^ + (sum f~i~)^2^ ]^1/2^

   From this definition, F(000) is non-negative definite i.e. it is zero 
or positive, i.e. it is an amplitude, consequently

> non-dispersive F(000) (which may be negative)

makes no sense.

H.
_______________________________________________
coreDMG mailing list
coreDMG@iucr.org
http://mailman.iucr.org/mailman/listinfo/coredmg

[Send comment to list secretary]
[Reply to list (subscribers only)]