Some remarks on the ionic radii of iron‐group elements. The influence of crystalline field

Abstract

Abstract The ionic radii of iron group elements do not decrease monotonically from Ca towards Zn but show maxima at configurations d 4 , d 5 and–possibly–d 9 , d 10 . An explanation is offered. It is based upon a heteropolar model where the influence of the other ions on the electronic distribution of 3d electrons is considered as a purely electrostatic influence of their net charges. The maxima are explained by the influence of a preponderantly cubic crystalline field, both for negliglible and strong interelectronic interaction.