Table 1. Data-collection and refinement statistics.

Data collection
X-ray source	Rotating anode
Wavelength (Å)	1.5418
Space group	R3(H)
Unit-cell parameters
a (Å)	85.2
b (Å)	85.2
c (Å)	45.5
Resolution (Å)	28–2.01 (2.12–2.01)
No. of unique observations	7993 (1019)
Redundancy	11.2 (10.6)
Completeness (%)	97.9 (85.8)
I/σ(I)	27.2 (8.2)
Rmerge† (%)	7.1 (31.2)
Refinement
Rconv‡ (%)	16.4
Rfree§ (%)	20.8
R.m.s.d., bond lengths (Å)	0.003
R.m.s.d., bond angles (°)	0.7
Mean B factor (Å2)	19.4

^† R _merge = , where I_i(hkl) is the intensity of an individual measurement of the reflection with Miller indices hkl and 〈I(hkl)〉 is the mean intensity of that reflection.

^‡ R _conv = , where |F _obs| and |F _calc| are the observed and calculated structure-factor amplitudes.

^§ R _free is equivalent to R _conv but calculated with reflections omitted from the refinement process (10% of reflections were omitted).