用耦合簇理论及相关一致五重基研究OH(X^2Π)自由基的光谱性质(英文)  

Accurate investigations on spectroscopic properties of OH(X^2Π)radical employing coupled-cluster theory in combination with the correlation-consistent quintuple basis set

作　　者：张金平[1] 陈丽[2] 施德恒[1] 孙金锋[3] 余本海[1] 

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,平顶山467000 [3]河南师范大学物理系,新乡453007

出　　处：《原子与分子物理学报》2008年第3期739-744,共6页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10574039);河南省高校科技创新人才支持计划(2008KJCX009);河南省教育厅自然科学计划项目(200510477001和2007140015)

摘　　要：利用耦合簇理论CCSD(T)和相关一致五重基aug-cc-pV5Z对OH自由基X2Π态的光谱性质进行了计算,获得的De,Re和ωe分别为4.6225 eV,0.09701 nm和3743.1644 cm-1,这与实验结果非常相符.在0.06-2.45 nm的核间距范围内对OH(X2Π)进行单点能计算,并将计算结果拟合成了Murrell-Sorbie函数.利用得到的解析势能函数,首先计算了该自由基的其余3个光谱常数(ωeχe,eα和Be),其结果与实验值也很相符.接着通过求解双原子分子核运动的径向Schr dinger方程,找到了J=0时OH(X2Π)的全部15个振动态.最后还计算了每一振动态的振动能级、振动经典转折点、惯性转动常数和离心畸变常数.The spectroscopic properties of the OH（X^2Ⅱ） radical have been investigated by using the coupled-duster singles-doubles-approximate-triples [ CCSD（T）] theory in combination with the augmented correlation-consistent polarized valence basis set of quintuple-zeta quality （aug-cc-pV5Z）. The present De, Re,ωe results are of 4.6225 eV, 0.09701 nm, 3743.1644 cm^-1, respectively, which are in excellent agreement with the measurements. The adiabatic potential energy curve is calculated over the internuclear separation range from 0.06 to 2.45 nm and is fitted into the analytic Murrell-Sorbie function. By comparisons with other theories, the derived spectroscopic constants（ωeХe,αe and Be） show a good accord with the experiments. With the potential obtained at the CCSD（T）/aug-cc-pV5Z level of theory, a total of 15 vibrational states has been found when J = 0 for the first time by numerically solving the radical Schrodinger equation of nuclear motion. For each vibrational state, the vibrational level, classical turning points and inertial rotation and centrifugal distortion constants are reported.

关 键 词：势能函数 光谱常数 离解能 振动能级 

分 类 号：O561.1[理学—原子与分子物理]