The two-center one-electron integral Hμν  

Sometimes called the resonance integral, Hμν is approximated using the overlap integral, Sμν. Note that this violates the NDO approximation, but since resonance integrals are large, this integral is retained. This is the origin of Modified in the name of the method. With Slater atomic orbitals of type

ψμ  = Nrn-1e-xr

the overlap integral is given by:

Sμν= <ψμψμ>

Hμνis approximated by:

Hμν = Sμν½ (βμ βμ)