分子几何构型是分子结构及化学键理论的基本问题之一。由现代的实验技术或精细的量子化学计算得到分子几何构型,虽然已不是什么很困难的事,然而从实用的角度来看,以一种十分简明的规则直接了当地说明它,仍是人们一直关心的有趣课题。在讨论中心原子为非过渡族元素的AB_n型分子时,Gillespie在sidgwick和Pawell推斥力假设的基础上,提出了价壳层电子对排斥理论(VSEPR),成功地说明 Molecular geometry is one of the basic problems in molecular structure and chemical bonding theory. Although it is hardly a difficult task to calculate the molecular geometry by modern experimental techniques or elaborate quantum chemistry calculations, it is still a matter of practicality that a straightforward account of a molecular structure Interesting topic that has always been concerned. In discussing AB_n-type molecules whose central atoms are non-transitional group elements, Gillespie proposed the valence shell electron exclusion theory (VSEPR) based on the sidgwick and Pawell repulsion assumption,