TABLE I.

Data Collection and Phasing Statistics

Space group	I222			C2
Cell dimension (Å)	a = 69.8, b = 132.3, c = 141.0			a = 109.3, b = 109.1, c = 179.1, β = 107.6°
Number of molecules in the asymmetric unit	4			12
MAD data statistics	λ1	λ2	λ3	λ4
Wavelength (Å)	0.9790	0.9787	0.9500	0.9500
Resolution (Å)	2.3	2.3	2.3	1.67
Observed reflections	152,088	158,161	156,359	661,828
Unique reflections	28,175	28,788	28,823	199,616
Completeness (%)a	97.4 (94.7)	97.8 (95.9)	97.4 (94.6)	86.1 (49.3)
Rmerge (%)b	8.7 (9.7)	8.9 (17.1)	7.3 (17.6)	7.4 (21.3)
〈I/σ(I)〉	9.5	10.0	9.9	12.0
MAD phasing statistics (reference data set at λ2)
Phasing powerc	1.02	—	1.04
Dispersive Rd	0.92	—	0.94
Anomalous Re	0.72	0.72	0.77
Figure of merit	0.49

^aThe values in parentheses are for the highest resolution shell: 2.40–2.30 Å for the I222 space group and 1.75–1.67 Å for the C2 space group.

^bR_merge = Σ_hkl[(Σ_j|I_j − 〈I〉|)/Σ_j|I_j|].

^cPhasing power = Σ_j|F_H|/Σ_j|E|, where E is the lack of closure error.

^dDispersive R = Σ_hkl||F_P + F_H(calc)| − F_PH|/Σ_hkl|F_PH − F_P|, where F_P corresponds to the reference data set λ₂ and F_PH corresponds to data collected at λ₁ or λ₃.

^eAnomalous $R={\sum }_{\mathit{hkl}}\mid \mathrm{\Delta }{F}_{\text{obs}}^{\pm }-\mathrm{\Delta }{F}_{\text{calc}}^{\pm }\mid /{\sum }_{\mathit{hkl}}\mid \mathrm{\Delta }{F}_{\text{obs}}^{\pm }\mid$, where ΔF^± is the structure factor difference between Friedel pairs.