在小硅化物SiX^m（X＝Be、B、C、N、O、F、Ne，m＝～4－＋2）中分子成键倾向的从头算研究

AB IXITIO MOLECULAR ORBITAL STUDY OF BONDING TRENDS IN SIX￣m SYSTEM(X=Be,B,C, N, O,F,Ne; m=-4～+2)

此文用从头计算法，在ＨＦ、ＭＰ２、ＭＰ３水平下，使用基组６—３１Ｇ、６—３１＋Ｇ对ＳｉＯ的等电子分子ＳｉＸｍ（Ｘ＝Ｂｅ、Ｂ、Ｃ、Ｎ、Ｐ、Ｎｅ，ｍ＝－４～＋２）进行了几何优化，并计算了相应的平衡几何构型下的振动频率，对ＳｉＯ分子，使用ＱＣＩＳＤ（Ｔ）方法考虑了不同水平下的电子相关效应，并考虑了不同基函数６－３１＋Ｇ和６－３１１＋Ｇ的影响。计算结果表明，所有分子的势能曲线都有稳定的极小值，并且键长与频率在ＨＦ、ＭＰ２、ＭＰ３水平上都呈现出明显的规律性，通过与实验上存在的稳定分子ＳｉＯ相比较，可以预言ＮＳＩｉ－和ＳｉＦ＋比其它分子有较明显的成键可能性，所以，ＮＳｉ－和ＳｉＦ＋有可能形成稳定的分子。

The equibrium geometries and harmonic vibrational frequences of the ground electronicstates of SiXm(X= Be, B, C, N, O, F, Ne ; m=-4～+2) have been studied by ah intio method.Calculated results indicate that all species considered have a local mimium, the bond length andfrequence show obviously trends. cornparing with experimentally know molecular Sio. Thespecies NSi- and SiF+ have larger probability of bonding trends than other species. It could beexpected that NSi- and SiF+ could be Candidates of probobly stable new moleculars.