In this paper CNDO / 2 and supermolecule approach were used to study the relationship between electronic structures and the substituted group effect for substituted acetic acids in aqueous solution .

本文应用量子化学理论、 超分子 方法和CNDO／2计算方法，结合 回归 分析研究水溶液中取代乙酸的取代基效应与分子的电子结构的关系。并分析在水溶液中取代基效应 被 削弱 的 原因。

The intermolecular potential energy surface for HeLi_2 has been calculated by supermolecule method and CCSD ( T ) approach with a large basis set .

采用 超分子单双迭代耦合簇CCSD（T） 方法和大基组，计算得到了He-Li2体系基态的全程势能面。

CNDO / 2 and supermolecule approach coupled with regression analysis was used to study seven hydration model selected . The best hydration model which can simulate the substituted acids in aqueous solution was determined .

应用量子化学理论、 超分子 方法和CNDO／2计算 方法，结合回归分析，对所选的7种模型进行量化计算，从中得出能模拟水溶液中羧酸的最佳量化计算模型。