CdF分子基态和低激发态的多参考组态理论研究

MRCI calculations for ground and excited states of CdF molecule

采用含Davidson修正的多参考组态相互作用方法(MRCI+Q),对F原子和Cd原子分别使用相关一致基augcc-p VQZ和相对论赝势基aug-cc-pwCVQZ-PP,对CdF分子对应最低两个离解限Cd(~1S_g)+F(~2P_u)和Cd(~3P_u)+F(~2P_u)的14个电子态~2S^+(3),~2∏(3),~4∑^+(2),~4∏(2),^(2,4)△,^(2,4)∑^-,在核间距R=1.3-6.0?之间进行了Λ-S态势能曲线计算。理论计算结果表明,X^2Σ+,2~2S^+,2~2Π,3~2∑^+为束缚态,而1~2Π,3~2Π,1~2∑^-,1~2Δ,1~4∑^+,2~4∑^+,1~4Π,2~4Π,1~4Δ,1~4∑^-为排斥态,两个离解限能量间隔为30 147cm^(-1)。随后,依据Λ-S束缚态势能曲线,对X^2S+,2~2∑^+和2~2Π进行了振动能级和转动常数的计算。上述计算结果跟已有的实验值比较接近。

The potential energy curves（PECs） of Cd F correlating to the first two dissociation asymptotes Cd（^1S_g） ＋ F（^2P_u）and Cd（^3P_u）＋F（^2P_u） were computed by using multi-reference configuration interaction including Davidson correction（MRCI＋Q）approach. The PECs of the fourteen states（^2∑^＋3）,^2∏（3）,^4∑^＋2）,^4∏（2）,^2,4Δ, and^2,4Σ^-） were calculated in the internuclear distance range from 1.3 to 6.0 angstrom at the basis sets, aug-cc-p VQZ for F and aug-cc-pw CVQZ-PP for Cd atom. The calculated results show that X^2∑^＋ 2^2∑^＋ 2^2Π, 3^2∑^＋re bound, while 1^2Π, 3^2Π, 1^2Σ^- 1^2Δ,1^4∑^＋ 2^4∑^＋ 1^4Π,2^4Π,1^4Δ,1^4Σ^-re repulsive. The energy gap of the second and the first dissociation limit is 30 147 cm^-1. Based on the computed PECs of X^2S^＋,2^2S^＋ and 2^2Π, the vibrational level and rotational constant were obtained, which are in good accordance with the available experimental data.