HC_nS^+和HSC_n^+(n=1～9)结构的 ab initio 研究  

Ab initio Calculations on the Structures of HCnS+ and HSC+n (n=1～9)

作　　者：刘朝阳[1] 黄荣彬[1] 郑兰荪[1] 

机构地区：[1]固体表面物理化学国家重点实验室厦门大学化学系

出　　处：《Chinese Journal of Chemical Physics》1997年第5期413-417,共5页化学物理学报（英文）

基　　金：国家教委"跨世纪优秀人才计划"基金

摘　　要：应用量子化学从头计算方法，在ＨＦ／６－３１Ｇ＊水平上，采用Ｂｅｒｎｙ优化法，优化了ＨＣｎＳ＋和ＨＳＣ＋ｎ（ｎ＝１～９）两种同分异构簇离子的几何构型，计算了它们的电子总能量、相邻簇离子的能量差及其平均原子结合能。计算结果表明，ＨＣｎＳ＋比相应的ＨＳＣ＋ｎ稳定。计算结果还显示，无论是优化后的几何构型，还是各种能量值，均显示出明显的奇偶交替变化的趋势，ｎ为奇数的簇离子比相应的ｎ为偶数的簇离子稳定，这和以前得到的实验结果完全相符。此外，还计算了ＨＣｎＳ＋分别碎裂Ｈ、ＨＣ、ＨＣ２、Ｓ、ＣＳ与Ｃ２Ｓ六条解离途径的解离能。计算结果同样证明成簇碳原子数为奇数的簇离子比较稳定。Carbon cluster ions with a sulfur atom and a hydrogen atom have been generated in the experiments. The recorded mass spectra show that the cluster ions with odd number of clustering carbon atoms are more stable. To verify the experimental observations, ab initio calculations on HF/6-31G* level were carried on the species. Two structural isomers, HCnS+ and HSC+n, have been considered in the calculation, and the former is found to be more stable. Based on the optimized geometry, the total system energy, the energy difference between the neighboring cluster ions, the average binding energy per clustering carbon atom and the fragmentation energies of six dissociation channels have been calculated. All calculated results exhibit the odd/even alternation and indicate that the cluster ions with odd n are more stable, which agrees very well with the experimental results.

关 键 词：结构稳定性 解离能 碳原子簇 从头算 

分 类 号：O613.71[理学—无机化学]