Calculation of the Electron Density of a Hexagonal Unit Cell from Diffraction Data (Example).




As an example, the electron density of a hexagonal unit cell is calculated from diffraction data. We take the experimental data from the paper Harper et al. 2001 [1], for fully hydrated aqueous dispersions of the phospholipid DEPE (Di-“elaidoyl”-phosphatidylethanolamine) at 85°C. The first 7 reflextions of the hexagonal are given with 1.00/0.88/0.73/0.10/0.17/0.18/0.14 which are the Lorentz- and multiplicity-corrected amplitudes with the signs +/-/-/+/+/+/+. The hexagonal lattice spacing of the lipid at 85°C is 69.9 A.

The parameters for the calculation are entered as input into the Electron density calculator for 2D-hexagonal or 2D-square lattices as shown below:


The results (e-density of the hexagonal phase) are plotted in 3D and 2D:






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Author: M.Kriechbaum, TU-Graz (2020), e-mail: manfred.kriechbaum@tugraz.at