Hello All, Does anyone know of a reference that explicitly shows that sigma2 for a linear backscattering path is approximately twice a single scattering path? My example is for a uranyl moiety (UO2). The structure of this moiety is symmetric and linear with a dumbbell shape with O1=U=O2 all in a row. I need a reference that does the calculation to show that the 4 leg path (U-O1-U-O2-U) has a sigma2 value that is twice the single scattering path (U-O1-U) from one of the oxygen atoms. Thanks for your help Shelly
Hi Shelly, On Thu, 30 Oct 2003, Kelly, Shelly D. wrote:
Hello All,
Does anyone know of a reference that explicitly shows that sigma2 for a linear backscattering path is approximately twice a single scattering path?
I think one can show that this approximation is justfied to some
extent by the large difference in masses between U and O atoms.
One can always calculate any MS sigma2 as <(delta R)**2>
delta R = sum_i (u_i-u_i+1)dot ^r_i,i+1
where u_i is the displacement at site i. This gives sigma2 as a
sum of correlation functions
My example is for a uranyl moiety (UO2). The structure of this moiety is symmetric and linear with a dumbbell shape with O1=U=O2 all in a row. I need a reference that does the calculation to show that the 4 leg path (U-O1-U-O2-U) has a sigma2 value that is twice the single scattering path (U-O1-U) from one of the oxygen atoms.
For the single scattering path (U-O1-U) this gives
sigma2_(U-O)= + - 2
participants (2)
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John J. Rehr
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Kelly, Shelly D.