Hückel transformation theory of ground state HF

In the elementary Hückel theory of ground state HF at its simplest valence level the two unknown parameters ∣αp − αh∣ and ∣β∣ can be determined in terms of experimental bond dissociation energy and electric dipole moment. If some sp hybridization is admitted on F in a bond orbital approximation, optimization of the resulting Hückel energy against the hybridization parameter ω using 1-term SCF/STOs shows that little hybridization (ω ≈ 8°) gives a 3% increase in the bond energy parameter ∣β∣ and a 14% reduction in the value of the formal charges ∣δ∣ on the interacting atoms.