The one-center one-electron integral Hμμ

This represents the energy an electron in atomic orbital fm would have if all electrons were removed from the system. This is approximated by adding on to the one-electron energy of the atomic orbital in the fully ionized atom the potential due to all the other nuclei in the system. The one-electron energy is obtained parametrically, and is given the symbol Uμν. Hμν is derived from the fundamental equation

Hμμ = Uμμ -ΣΒ ≠Α ZB<μμ|BB>

by equating the core-electron integral <μμ|BB> to the corresponding two-electron integral, thus:

<μμ|BB> = ZB<μμ|ss>