7Li2分子23Πu激发态的解析势能函数、振动能级及其转动惯量

使用Gaussian 03程序包中的“对称性匹配簇-组态相互作用”方法、在0.13—2.0nm的核间距范围内利用6-311+〖KG-*3〗+G(d,p)基组对⁷Li₂(2³Π_u)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, 计算了该态的谐振频率, 进而计算了该态的其他光谱常数, 分别为T关键词： 解析势能函数 谐振频率 振动能级 转动惯量

Investigation of analytic potential energy function, vibrational levels and inertial rotation constants for the 23Πu state of spin-aligned dimer 7Li2

Using the symmetry-adapted-cluster-configuration-interaction (SAC-CI) method provided by the Gaussian 03 program package, the potential energy curve for ⁷Li₂(2³Π_u) has been calculated with the basis set 6-311++G(d,p) over the internuclear separation range from 0.13 to 2.0 nm. And the ab initio calculated points have been subjected to a least squares fitting to Murrell-Sorbie function. Employing the Rydberg-Klein-Rees method, the harmonic frequency is derived from the analytic potential energy function and then other spectroscopic data are further computed. These spectroscopic data are T_e=3.6701eV, D_e=1.0764eV, R_e=0.3000nm, ω_e=285.69cm^-1, ω_eχ_e=1.8351cm^-1, α_e=0.00942cm^-1 and B_e=0.5340cm^-1, respectively. In particular, the present T_e, D_e, R_e and ω_e　values are in excellent agreement with other theoretical results. With the analytic potential energy function obtained on the SAC-CI/6-311++G(d,p) level, a total number of 67 vibrational states for the 2³Π_u state is found when J=0 by solving the radial Schrdinger equation of nuclear motion. The complete vibrational levels, classical turning points and inertial rotation constants for these vibrational states are also reported. The reasonable dissociation limit for the 2³Π_u state is deduced using the present results calculated.