Data collection and refinement statistics.

(a) Values in parenthesis correspond to the outermost resolution shell. The data were recorded from a single crystal.
(b) Rfactor = ∑||Fo|−|Fc||/∑|Fo| where |Fo| and |Fc| are observed and calculated structure factor amplitudes, respectively.
(c) Free Rfactor is the cross-validation R-factor computed for a randomly chosen subset of 5% of the total number of reflections, which were not used during refinement.