Mulliken布居对键强度判断的经验修正

• 作 者: 李新华 朱龙观 俞庆森
• 机 构: 浙江大学玉泉校区化学系!杭州310027,浙江大学玉泉校区化学系!杭州310027,浙江大学玉泉校区化学系!杭州310027
• 出 处: 高等学校化学学报
• 发表日期: 2000年07期
• 关键词: Mulliken布居 键强度 修正公式

We modified Mulikens overlap population n(A, B)=2∑Bλ∑Aμ∑in_ic~*_A,μic_B,λis_Aμ,Bλ 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_AN~2_A(2∑Bλ∑Aμ∑i}n_ic~*_A,μic_B,λis_Aμ,Bλ), N_B(A, B)=Z_BN~2_B(2∑Bλ∑Aμ∑in_ic~*_A,μic_B,λis_Aμ,Bλ). Twenty-eight bonds calculated by IEHM method and 11 monohydrides calculated by using 6-31G~** 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.

We modified Mulikens overlap population n (A, B) = 2ΣBλΣAμΣin_ic ~ * _A, μic_B, λis_Aμ, Bλ 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_AN ~ 2_A (2ΣBλΣAμΣi n_ic ~ * _A, μic_B, λis_Aμ, Bλ), N_B , B) = Z_BN ~ 2_B (2ΣBλΣAμΣin_ic ~ * _A, μic_B, λis_Aμ, Bλ) Twenty-eight bonds calculated by IEHM method and 11 monohydrides calculated by using 6-31G ~ ** basis sets at Hartree 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 .