AlCl分子X^1∑^+电子态的光谱性质  

Study on spectroscopic properties of AlCl(X^1∑^+) molecule

作　　者：刘慧[1] 苏跃林[2] 施德恒[3] 

机构地区：[1]信阳师范学院物理电子工程学院,信阳464000 [2]平顶山教育学院物理系,平顶山467000 [3]河南师范大学物理与信息工程学院,新乡453007

出　　处：《原子与分子物理学报》2013年第5期715-722,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(60777012);河南省科技计划项目(122300410303)

摘　　要：运用耦合簇单双取代三重微扰方法[CCSD(T)]和内收缩多参考组态相互作用方法(MRCI)结合系列相关一致基,aug-cc-pV(n+d)Z(n=D,T,Q,5,6),研究了AlCl(X1∑+)分子的光谱性质.比较了两种理论方法及不同的基组对AlCl(X1∑+)分子的光谱常数的影响.在优选的MRCI/aug-cc-pV(5+d)Z理论水平下于0.05~2.0nm核间距范围内计算了AlCl(X1∑+)分子的势能曲线.拟合势能曲线得到其光谱常数De,D0,Re,ωe,ωexe,Be和αe.它们分别为5.1942eV,5.1644eV,0.21350nm,481.67cm-1,2.1022cm-1,0.2416cm-1和0.0016cm-1.这些结果与已有的实验结果均较为相符.利用这一势能曲线,通过求解双原子分子核运动的径向Schrdinger方程,计算了AlCl分子基态的振转能级.找到了J=0时的全部182个振动态.针对每一振动态,还分别计算了其对应的振动能级、惯性转动常数和离心畸变常数等分子常数.文中的大部分分子常数属首次报导.The equilibrium parameters （De, Re and ωe） for the A1CI（X1 ∑＋） molecule have been studied using the coupled-cluster singles-doubles-approximate-triples [CCSD（T）] theory and internally contract- ed multireference configuration interaction （MRCI） approach. A series of correlation-consistent basis sets in the valence range, aug-cc-pV（n＋d）Z（n = D, T, Q, 5）, are used in the calculations. At the CCSD（T） and MRCI levels of theory, the effects on the spectroscopic parameters by different basis sets are studied. The accurate potential energy curve is calculated at the MRCI/aug-cc-pV（5＋d）Z level of theory over the internclear separation range from 0.05 nm to 2.0 nm. With the potential obtained here, the spectroscopic parameters （De, D0, Re, ωe, ωexe, B, and at） of the A1CI（X1 ∑＋ ） molecule are deter- mined. These spectroscopic parameters are 5. 1942 eV, 5. 1644 eV, 0. 21350 nm, 481.67 cm-1 , 2. 1022 cm-1 , 0. 2416 cm-1 , and 0. 0016 cm-1 , respectively. These results are in excellent agreement with the available experiments. With the potential energy curve obtained at the MRCI/aug-ec-pV（5 ＋d）Z level of theory, the vi-robrational spectrum for A1CI（X1 ∑＋ ） are determined by numerically solving the radicalSchr6dinger equation of nuclear motion, and the vibrational levels and their corresponding inertial ro-vibrational levels are calculated. The complete 182 rotation and centrifugal distortion constants are deter mined when J = 0 for the first time.

关 键 词：势能曲线 振转能级 分子常数 光谱常数 

分 类 号：O561.1[理学—原子与分子物理]