And so this is what it will look like when it will be bound to that diatomic oxygen. So this is a diatomic oxygen that is bound to this metal atom, and it pulls away the electron density, decreasing the size of the metal atom. And now the metal atom is able to fit into the center of that protoporphine plane. Now, what exactly is the structure that describes this complex here? Well, this complex between the metal atom and the diatomic oxygen can be described by a resonant stabilized structure as shown on the board. So these are the two electron structures that describe the resonance stabilized complex between our fe atom and the diatomic oxygen.