1	FS0	Fe2/s3 cluster	1.000
2	FES	Fe2/s2 (inorganic) cluster	0.800
3	F3S	Fe3-s4 cluster	0.714
4	F4S	Fe4-s3 cluster	0.714
5	SF3	Fe4-s3 cluster	0.714
6	VV2	Fe-S cluster	0.714