Table 1.

Selected structural parameters of the three optimized structural models of the BNC harbouring either a cyanate (model 1a, model 1b) ligand or an uretdione ligand (model 2) compared to crystal structure (PDB entry: 2GSM).

	Crystal	Model 1a	Model 1b	Model 2
Ligand	O2	(Fe) OCN− (Cu)	(Fe) NCO− (Cu)	(NCO)2−
RMSD		3.96	0.86	4.59
Fe … CuB	4.89	5.59	5.30	5.52
Fe …OCN− (1a)
Fe …NCO− (1b)		2.014	1.881	1.852
Fe …NCO2− (2)
Cu …NCO− (1a)
Cu…OCN− (1b)		1.956	2.184	1.948
Cu …NCO2− (2)
Fe …N(heme a3)	2.065	2.012	2.002	2.026
	2.089	1.992	1.958	2.000
	2.095	2.002	2.036	1.976
	2.135	2.016	2.045	1.978
	(2.096)	(2.006)	(2.010)	(1.995)
Fe …N(H419)	2.109	1.944	1.980	2.026
CuB…N(H284)	2.061	2.041	2.000	2.029
CuB…N(H333)	2.062	2.057	2.051	2.017
CuB…N(H334)	2.080	2.011	2.006	2.088
Mulliken charges
Fe		0.514	0.467	0.532
CuB		0.386	0.408	0.408

Atomic distances as well as root mean square deviation (RMSD) of the position of heavy atoms relative to their crystal arrangement after alignment of Cβ atoms, are given in Å.