理论研究BeS(X^1∑^+)的光谱常数及分子常数  

Investigation on spectroscopic parameters and molecular constants of BeS(X^1∑^+) using MRCI theory

作　　者：刘慧[1] 邢伟[1] 施德恒[2] 孙金峰[2] 

机构地区：[1]信阳师范学院物理电子工程学院,信阳464000 [2]河南师范大学物理系,新乡453007

出　　处：《原子与分子物理学报》2012年第2期216-222,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(60777012);河南省高校科技创新人才支持计划(2008HASTIT 008);河南省教育厅自然科学研究计划(2010B140013)

摘　　要：采用Davidson校正的内收缩多参考组态相互作用方法(MRCI+Q)结合相关一致五重基cc-pV5Z在二阶Douglas-Kroll Hamiltonian近似下,计算了BeS分子X^1∑^+态的势能曲线.对势能曲线进行核价相关效应修正计算,得到了同时含有核价相关效应修正及相对论效应的势能曲线.拟合修正的势能曲线,获得BeS(X^1∑^+)的光谱常数R_e,ω_e,ω_ex_e,ω_ey_e,B_e,α_e,β和D_0,分别为:0.17429 nm,997.06cm^(-1),6.1056 cm^(-1),0.0041 cm^(-1),0.7893 cm^(-1),0.006657 cm^(-1),6.8002×10^(-9)cm^(-1)和4.2609 eV.与已有的实验结果及其它理论结果的比较表明,本文BeS(X^1∑^+)的光谱常数的计算结果达到了较高的精度.通过求解双原子分子核运动的径向Schr(o|¨)nger方程,找到了非转动BeS(X^1∑^+)的前40个振动态.针对每一振动态还分别计算了相应的振动能级、惯性转动常数和离心畸变常数等分子常数.The potential energy curve （PEC） of BeSmolecule has been studied using MRCI ap proach with Davidson modification in conjunction with the ccpVSZ basis set. Effects on the PECs by the corevalence correlation corrections and relativistic effects have been taken into account. The way to con sider the relativistic effects is to use the secondorder DouglasKroll Hamiltonian approximation. With the PEC including the corevalence correlation corrections and relativistic effects, the spectroscopic pa rameters of BeS have been determined. These parameters are compared in detail with those of previous studies reported in the literature, and excellent agreement has been found between the available experimental data and the present ones. With the PEC corrected, the first 40 vibrational states for the nonrotating BeS are computed, and the vibrational level, inertial rotation and centrifugal distortion con stants for each vibrational state are predicted.

关 键 词：势能曲线 光谱常数 分子常数 MRCI理论 

分 类 号：O561.1[理学—原子与分子物理]