. Author manuscript; available in PMC: 2012 Nov 23.

Published in final edited form as: J Am Chem Soc. 2011 Oct 28;133(46):18656–18662. doi: 10.1021/ja203780t

Table 1.

Optimized Bondlengths of the Calculated Models (Å)^a

	Fe-μ₃S_sulfide	Fe-S_thiolate	Fe-O	Fe-N	S_SAM-Fe	S_SAM-μ₃S_sulfide
Model A	2.28	2.24	2.21
Model B	2.29	2.28	1.87
Model C	2.30	2.28	2.06	2.32
Model D	2.31	2.24	2.22	2.34	3.45	3.78
*X-Ray*
PFL-AE¹⁰ (2.77 Å)	(2.30)	(2.27)	(2.12)	(2.17)	(3.22)	(3.97)
HydE¹⁶ (1.62 Å)	(2.30)	(2.29)	(2.25)	(2.33)	(3.25)	(3.90)

These theoretical active site models represent unconstrained geometry minima. Thus the optimized parameters are compared to both high and low resolution structures of SAM bound cluster. The higher resolution of the HydE structure justifies the comparison of the bond lengths up to two decimal places.