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. 2022 Mar 16;78(Pt 2):195–213. doi: 10.1107/S2052520622001500

Table 5. Stages in the evolution of the SDPD of DCQ for the structure that finally turned out to be the correct one.

The initial random trial structure (GO1–GO2) in P1 evolved through the fitting steps of the global optimization run (GO3–GO4) and went through automatic cell transformation and re-evaluation fine fit (RE). It was then transformed to Inline graphic and subjected to the final user-controlled Rietveld refinement (UR). The similarity values S 12(l) refer to the comparison of the simulated pattern to the background-corrected experimental pattern based on the 2θ comparison range set for the global optimization. Inline graphic refers to the comparison of the powder pattern simulated by TOPAS and the experimental pattern. E FF denotes the force-field energy.

  Random Fast raw fit Better fit 1 Better fit 2 Automatic transformation Re-evaluation fit Final Rietveld refinement
  GO2 GO3 GO4 GO4 RE1 RE2   UR
Space group (Z) P1 (Z = 1) P1 (Z = 1) P1 (Z = 1) P1 (Z = 1) P1 (Z = 1) P1 (Z = 1)   Inline graphic (Z = 1)
l (°) 1.0 0.72 0.58 0.43   0.1    
Similarity S 12(l) 0.7331 0.8997 0.9615 0.9536   0.9714    
Reference similarity       Inline graphic Inline graphic Inline graphic   Inline graphic
        0.9186 0.9836 0.9868   0.9969
V/Z (Å3 mol−1) 355.07 388.16 388.93 389.58 389.58 391.08   377.20
a (Å) 3.868 3.797 3.797 3.797 3.797 3.797   3.772
b (Å) 5.888 6.442 6.508 6.521 6.521 6.551   6.479
c (Å) 15.944 16.233 16.132 16.131 16.131 16.125   15.774
α (°) 85.99 86.53 85.30 85.04 94.96 95.33   93.74
β (°) 90.85 90.74 91.14 91.14 91.14 91.14   92.19
γ (°) 78.68 78.41 78.41 78.41 101.59 101.49   100.92
Δφ x (°) −15.9 −15.8 −24.3 −25.2     R exp (%) 4.599
Δφ y (°) −66.5 −66.3 −64.7 −64.5     R wp (%) 5.219
Δφ z (°) 24.6 25.0 34.4 35.2     R wp′ (%) 8.438
E FF (kJ mol−1) −115.3   −207.7 −207.4     GoF 1.135