微扰分子轨道(Perturbational molecular orbital,PMO)法能通过简单的计算对有机分子的反应性和稳定性给以很好定性的推测以及统一许多化学行为。此方法不是孤立地分析每一个体系而是计算体系之间的差异,然后说明之。近似PMO法是从非键分子轨道近似法(Nonbonded Molecular Orbital Approximation)及成对原理(Pairing theorem)(交替烃,AH’s)发展而来的,它适用于处理共轭烃的芳香性、杂原子对共轭体系的影响、亲电和亲核芳香族取代反应、消除——加成反应、亲核脂肪族取代反应、周环反应、π络合物稳定性 The Perturbational Molecular Orbital (PMO) method gives a good qualitative presumption and unification of many chemical behaviors through simple calculations of the reactivity and stability of organic molecules. This method does not analyze each system in isolation but calculates the differences between the systems, and then explains. The approximate PMO method is developed from the Nonbonded Molecular Orbital Approximation and the Pairing Theorem (Alternating Hydrocarbons, AH’s) and is suitable for handling the aromaticity of conjugated hydrocarbons, the heteroatom pair Conjugation effects, electrophilic and nucleophilic aromatic substitution reactions, elimination-addition reactions, nucleophilic aliphatic substitution reactions, cyclical reactions, π-complex stability