"Diffraction by helical structures"

Date:
1956-1957
Reference:
PP/CRI/H/2/17
Catalogue details

Licence: In copyright

Credit: "Diffraction by helical structures". Source: Wellcome Collection.

    24/98
    O • 17 » ^ I 9 n /(V) ^ % *7), ,1 - JJ ö-K^ (n)Anfí.*a J n (^¿ r ) ^ ¿r To reduce the double integrâï «e use the result and henee Osi+ój (a ^ ,iU/ utssr« J T a (airM - ¿¡-/? y/' Mí ¿z **,-«. - ^ CR) mk. Í^MMA /wtuWlAfrj J^¿ÁaJX*rKá Ö ^ j <x^c Í3D) VJ \M^if I fili (Mllf ¿&díZy. anè-w m I bo » fro» fê4sr> M Equations and <27) show how to make a Fourier synthesis of a cylindrical projection from the diffraction data* But sinee the determination of the Fourier coefficients A # would seem to require prióf ^ pir&r knowledge of the whole course of G„ c (R) as a function of E n # -, it would be more reàlistic to construct the full three-dimensional electron density*. If there were some simple means of estimating say^ the average value of G ß then this synthesis might prove very valuable indeed. VJ ^...Pja^l^aCL^nngtlnOQ .of We shall now consider what information may be obtained directly from the intensities, when we have no knowledge of the phases# If we had three-dimensional data we could of course construct the Patterson function, but as mentioned earlier, the only data we usually have is from a fibre diagram and this leads to the cylindrically CK*i.r(H\SA aijeanged- iatterson. The latter is perfectly general and makes no