again the exact words you say are a wonderful description of how the chemical potential of an electron in a solid is defined besides the trivial exception that for electrons in solids it's usually expressed in ev rather than kcal mol the chemical potential is the partial derivative of the free energy with respect to the number of electrons in the solid in fact i wrote in wording just like that at the start of the electrons in solids section your main complaint now seems to be the introduction not the two physics sections that i just rewrote i did not write the introduction and i don't like it any more than you do i hope you rewrite it or else maybe i will when i get a chance i did however write the overview section