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Figure 4
The effect of inaccurate guiding unit cells on SPIND indexing rates and peak-prediction accuracy demonstrated on simulated I3C snapshot diffraction patterns. (a) Number of indexed patterns as a function of the α angle of the guiding cell (α = 90° is nominal). (b) Distribution of distance discrepancy in three-dimensional reciprocal space between found and predicted peaks for matched peak pairs using guiding cells with different α angle values. The legend shows the α angle of the guiding cell. The center of the distribution shifts to larger values as α deviates further from the nominal value of 90°. The same trend was observed for values of α < 90° (omitted for clarity). The results demonstrate the robustness of the algorithm to the lattice inhomogeneity, a wide tolerance range for the guiding-cell constants and low false-positive indexing rate when the target lattice cell is clearly distinguishable from the guiding cell. The indexing rate can be used as an indicator for the accuracy of the reference unit cell.

IUCrJ
Volume 6| Part 1| January 2019| Pages 72-84
ISSN: 2052-2525
https://doi.org/10.1107/S2052252518014951