Figure 2
Analyses of diffraction intensities: (a) and (b) form 1; (c) and (d) form 2. (a) and (c) show plots for cumulative intensity (I) distribution for acentric and centric reflections, where z is I/〈I〉 and N(z) is the percentage of reflections with intensities less than or equal to z. Observed curves for acentric (dots) and centric (crosses) are drawn as solid lines, and the expected theoretical curves for the untwinned case for acentric (squares) and centric (triangles) are drawn as broken lines. (b) and (d) show plots of the second moments (〈 I2〉/〈I〉2) of intensity, calculated using observed acentric data. The expected value for the untwinned case is 2.0, and that for the perfectly twinned case is 1.5. The mean value of the second moment is shown as a broken line. |