Fig. 7

Number of unpaired electrons for the Fe atoms in the stable a GR2 ×ばつ 6 models (all 5 shown) and b GR4 ×ばつ 6 models (only 5 shown for clarity, all 23 models are shown in Additional file 1: Figure S2). Fe atoms labeled with O, I and C refer to outer, inner and central atoms, respectively