SiH^(+)(X^(1)∑^(+))的势能曲线、光谱常数、振转能级和自旋-轨道耦合理论研究  

Accurate theoretical study of potential energy curves,spectroscopic parameters,vibrational energy levels and spin-orbit coupling interaction on SiH^(+)(X^(1)∑^(+)) ion

作　　者：高峰[1] 张红[1] 张常哲 赵文丽[1] 孟庆田[2] Gao Feng;Zhang Hong;Zhang Chang-Zhe;Zhao Wen-Li;Meng Qing-Tian(School of Information Science and Engineering,Shandong Agricultural University,Taian 271018,China;School of Physics and Electronics,Shandong Normal University,Jinan 250358,China)

机构地区：[1]山东农业大学信息科学与工程学院,泰安271018 [2]山东师范大学物理与电子科学学院,济南250358

出　　处：《物理学报》2021年第15期67-76,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11674198,11804195)资助的课题.

摘　　要：基于Molpro 2012程序包,应用包含Davidson修正的多参考组态相互作用方法,使用AVXZ和AVXdZ(X=T,Q,5,6)基组进行单点能从头算,然后采用Aguado-P aniagua函数进行拟合,得到了 SiH^(+)(X^(1)∑^(+))离子在不同基组、不同方法和是否考虑自旋-轨道耦合(SOC)情况下的解析势能函数(APEFs).以APEFs为基础,计算了SiH^(+)(X^(1)∑^(+))离子的解离能De,平衡键长Re,振动频率ωe,光谱常数Be,αe和ωeχe,同时讨论了 SOC对该体系的影响.本文的计算结果与其他理论计算符合得较好,与实验数值也基本吻合.基于SOC-AV6dZ方法下的APEF,通过求解径向薛定谔方程,给出了SiH^(+)(X^(1)∑^(+))离子的前23个振动能级(j=0),并详细列出了每1个振动能级及其相应的经典拐点,每个振动态的转动常数和6个离心畸变常数,且提供了振动能级图.该工作对于实验和后续的理论工作有参考和指导作用.The analytical potential energy function(APEF)of SiH^(+)(X^(1)∑^(+)) is fitted by Aguado-Paniagua function with 112 ab initio energy points,which are calculated by Molpro 2012 Package with the multi-reference configuration interaction including the Davidson correction method using AVX Z and AVX dZ(X=Q,5,6)basis sets.Moreover,the calculated ab initio energy points are subsequently extrapolated to complete basis set(CBS)limit to avoid the basis set superposition error.All the fitting parameters of APEFs for AV6Z,CBS(Q,5),AV6dZ,CBS(Qd,5d),SA-AV6dZ and SOC-AV6dZ methods are gathered.The potential energy curves(PEC)and the corresponding ab initio points are also shown.As can be seen,the PECs show excellent agreement with the ab initio points and a smooth behavior both in short range and long range,which ensures the high quality of fitting process for the current APEFs.Based on these APEFs of different basis sets and methods including AVQZ,AV5Z,AV6Z,CBS(Q,5),AVQdZ,AV5dZ,AV6dZ and CBS(Qd,5d),the spectral constants De,Re,we,Be,ae and wece are obtained.In addition,the effects of spin-orbit coupling interaction(SOC)on the system are also investigated.By comparing the spectral constants of SA-AV6dZ with the ones of SOC-AV6dZ,it is found that the effect of SOC on SiH^(+)(X^(1)∑^(+)) is small and can be ignored.We also compare the spectral constants in this work with the experimental values and other theoretical results.The results of this work accord well with the corresponding experimental and other theoretical results.It is worth noting that the deviation of dissociation energy between the theoretical calculations and experimental values is relatively large.Based on this conclusion,we suggest that the spectral constants including the dissociation energy for SiH^(+)(X^(1)∑^(+)) should be remeasured.Based on the APEF of SOC-AV6dZ which should be more accurate than others in theory,the top 23 vibrational states(j=0)of SiH^(+)(X^(1)∑^(+)) are calculated first by solving the radial Schrödinger equation.All the vibratio

关 键 词：SiH+(X1S+) 离子 势能曲线 光谱常数 自旋-轨道耦合 

分 类 号：O641[理学—物理化学]