Transmitting X rays through hemoglobin at the energy that would detach an electron from an iron atom enabled us to calculate the distance between iron and nitrogen atoms as the hemoglobin bound more and more oxygen.

• 让能量足以使一个电子脱离铁原子的X射线通过血红蛋白，我们就能计算出当血红蛋白同越来越多的氧结合时铁原子与氮原子之间的距离。