Combining data and calculation of projection map
For the preliminary set of projection data 20 crystalline areas were combined using rough estimates of phase origins. This data set enabled refinement of defocus values, phase origins and beam tilt. Amplitudes were averaged and scaled (18) and phases were set to either 0° or 180° before the projection density map was calculated. The accuracy of the data was analysed statistically. Fig 3a shows the overall average phase error and Fig 3b gives an estimation of the phase difference between two halves of data containing roughly equal information (16, 19).
Fig 3: Statistical analysis of the final data set with (red) and without (blue) beam tilt refinement. a) Estimated phase error on the whole data as a function of resolution. b) Comparison of the final estimates of phases of two independent halves of data. Random data are shown in yellow.
Schertler Group Page Home The Future   Gebhard Schertler, gfx@mrc-lmb.cam.ac.uk