H_(2)S和H_(2)S^(+)的振动光谱和电子能谱计算  

Vibrational spectra and photoelectron spectra calculations of H_(2)S and H_(2)S^(+)

作　　者：郭甜 徐建刚 张佳美 张思雨 陈艳南 张云光 GUO Tian;XU Jian-Gang;ZHANG Jia-Mei;ZHANG Si-Yu;CHEN Yan-Nan;ZHANG Yun-Guang(School of Science,Xi'an University of Posts and Telecommunications,Xi'an 710121,China)

机构地区：[1]西安邮电大学理学院,西安710121

出　　处：《原子与分子物理学报》2024年第4期27-34,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(22103061);陕西省自然科学基金(2022JQ-569)。

摘　　要：本文基于MOLPRO软件包使用从头算方法计算了星际分子H_(2)S及其阳离子H_(2)S^(+)的势能面及光电子能谱.首先,在(U)CCSD/cc-pVQZ理论水平下获取了H_(2)S沿法线坐标展开的势能面,势能面直观描述了不同振动模式耦合对分子能量变化的影响,S-H键的非对称伸缩振动和面内弯曲振动共同作用使得系统势能变化范围明显变大.振动多组态相互作用方法被用来计算非谐振动频率和振动光谱,计算结果显示,倍频和组合频之间出现了强烈的费米共振,使得相应波段处的红外强度显著增强.最后,使用拉曼波函数和收缩不变Krylov子空间方法首次计算了H_(2)SΧ^(1)A_(1)→H_(2)S+X^(2)B_(1)的光电子能谱.此项研究有助于进一步理解星际分子的内部结构,并为实验研究及星际观测提供参考.The potential energy surfaces and photoelectron spectra of the interstellar molecule H_(2)S and its cation H_(2)S^(+)were calculated using ab initio methods based on the MOLPRO software package.First,the potential energy surfaces of H_(2)S expanded along the normal coordinates were obtained at the(U)CCSD/cc-pVQZ level of theory.The potential energy surfaces visually describe the effect of different vibrational modes coupling on the molecular energy change,and the combined effect of the asymmetric stretching vibration of the S-H bond and the in-plane bending vibration makes the potential energy change range of the system significantly larger.The vibrational multi-reference configuration interaction method was used to calculate the anharmonic vibrational frequencies and vibrational spectrum,and the calculations showed that strong Fermi resonances appear between the overtones and combination bands,resulting in a significant enhancement of the infrared intensity at the corresponding bands.Finally,the photoelectron spectrum of H_(2)SX^(1)A_(1)→H_(2)S^(+)X^(2)B_(1)was calculated for the first time using the Raman wave function and the contracted invariant Krylov subspaces method.This study will help to further understand the internal structure of interstellar molecules and provide a reference for experimental studies and interstellar observations.

关 键 词：势能面 VMRCI 振动光谱 光电子能谱 

分 类 号：O561[理学—原子与分子物理]