Page "Chemical potential" Paragraph 53

Chemical potential of electrons in solids is closely related to the concepts of work function, fermi level, electronegativity, and ionization potential.

In fact, the chemical potential of an atom is sometimes said to be the negative of the atom's electronegativity.

Likewise, the process of chemical potential equalization is sometimes referred to as the process of electronegativity equalization.

This connection comes from the Mulliken definition of electronegativity.

By inserting the energetic definitions of the ionization potential and electron affinity into the Mulliken electronegativity, it is possible to show that the Mulliken chemical potential is a finite difference approximation of the electronic energy with respect to the number of electrons., i. e.,