Abstract: We modified Muliken's overlap population n(A, B)= and obtained an experiential formula N(A,B)=N_A(A,B)+N_B(A,B) of judging bond strength, where N_A(A, B)={Z_A/N_A², N_B(A, B)=Z_B/N_B². Twenty-eight bonds calculated by IEHMmethod and 11 monohydrides calculated by using₆-31G^** basis sets at Hartree-Fock level, electronic correlation effects are also considered through MP₂/6-31G^**, were used to verify our experiential formula. Compared with the judgment of chemical bond strength by means of Muliken's overlap population, our experiential formula has a more obvious improvement as a judgment of bond strength than Muliken's overlap population. As a judgment of chemical bond strength between atoms in molecules, the experiential formula has conquered some limitations of Muliken's overlap population, and accorded with the experimental results.

Key words: Muliken's overlap population, Bond strength, Modified formula