学术
^ 7Li2（X^1∑^＋g）分子的振动能级、转动惯量及离心畸变常数
施德恒[1,2] 孙金锋[2] 朱遵略[2,3] 马恒[2] 杨向东[3]
[1]信阳师范学院物理电子工程学院,信阳464000 [2]河南师范大学物理与信息工程学院,新乡453007 [3]四川大学原子与分子物理研究所,成都610065
摘 要:
使用密度泛函理论B3LYP和B3P86，以及组态相互作用方法CCSD（T）和QCISD，利用多个基组对^7Li2（X1∑^＋g）分子的平衡核间距（Re）、谐振频率（ωe）和离解能（De）进行了计算，发现在CCSD（T）／cc-PVQZ理论水平下得到的结果（Re=0.2698nm，ωe=346．82cm^-1和De=1.0487eV）与实验值非常相符．在0.15-2.7nm的核间距内对^7Li2（X1∑^＋g）分子的势能曲线进行了计算，同时使用最小二乘法将计算结果拟合成了解析势能函数。利用拟合出的解析势能函数并结合Rydberg-Klein-Rees方法，计算了光谱常数ωeχe，αe和Be，其值分别为ωeχe=2.648cm^-1，αe=0.00702cm^-1和Be=0.6601cm^-1，也与实验值非常相符，以得到的解析势能函数为基础，通过求解双原子分子核运动的径向Schrǒdinger方程，找到了J=0时^7Li2（X1∑^＋g）分子的全部41个振动态，求出了每一振动态的振动能级、振动经典转折点及其转动惯量，其值与实验结果相符得很好。同时，利用得到的解析势能函数，还首次求得了相应于各振动态的6个离心畸变常数（Dv，Hv，Lv，Mv，Nv和Ov）。[著者文摘]
文章出处:
《物理学报》-2008年57卷1期 -165-171页
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相关文章:
Investigation on vibrational levels, inertial rotation and centrifugal distortion constants of ^7Li2（X^1∑^＋g）
Shi De-Heng,Sun Jin-Feng,Zhu Zun-Lǔe,Ma Heng, Yang Xiang-Dong（1.College of Physics ＆ Electronic Engineering, Xinyang Normal University, Xinyang 464000, China;2.College of Physics ＆ Information Engineering, Henan Normal University, Xinxiang 453007, China;3.Institute of Atomlc ＆ Molecular Physics, Sichuan University, Chengdu 610065, China）
Abstract:
The density-functional theory （B3LYP, B3P86） and the configuration-interaction method （CCSD（T）, QCISD） presented in Gaussian03 program package are employed to calculate the equilibrium internuclear distance Re, the harmonic frequency ωe and the dissociation energy De of ^7Li2（X^1∑^＋g） under a number of basis sets. By comparison with the measurement, the conclusion is that the most accurate Re, De, and ωe results （0.2698 nm, 1.0487 eV and 346.82 cm^-1 , respectively） can be obtained at the CCSD（T）/cc-PVQZ level of theory. The potential energy curve at this level is calculated over a wide internuclear separation range of 0.15 to 2.7 nm at a 0.03 nm step size and is fitted to the analytic Murrell-Sorbie function. With the potential obtained at the CCSD（T）/cc-PVQZ level of theory, the rest spectroscopic parameters （ωe Xe , ae and Be） are calculated and the values are 2.648 cm^-1 , 0.00702 cm-l and 0.6601 cm^-1, respectively, which are in excellent agreement with the experimental ones.By solving the radial Schrǒdinger equation of nuclear motion, the total number of 41 vibrational states has been found when J=0 for this X^1∑^＋g state. For each vibrational state, the vibrational level, the classical turning point and the inertial rotation constant have been computed, which are in good agreement with the experimental findings. The complete centrifugal distortion constants （ Dv, Hv, Lv, Mv, Nv and Ov） are reported for the first time for the first 31 vibrational states when J=0.[著者文摘]
Key words:
analytic potential energy function, vibrational level, inertial rotation constant, centrifugal distortion constant
基金资助:
基金项目：国家自然科学基金（批准号：10574039）和河南省教育厅自然科学研究计划项目（批准号：2007140015）资助的课题.
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