HF分子电子基态和激发态的MRCI计算  

MRCI calculations forHF electronic ground and excited states

作　　者：侯圣伟[1] 张树东[1] 杨士玲[1] 董嫣然[1] 

机构地区：[1]曲阜师范大学物理系山东省激光偏光与信息技术重点实验室,曲阜273165

出　　处：《原子与分子物理学报》2013年第1期45-50,共6页Journal of Atomic and Molecular Physics

摘　　要：应用舍Davidson修正的多参考组态相互作用(MRCI)方法,在aug-cc-pVTZ基组水平上对HF基态及最低的多个单重和三重电子激发态进行了势能扫描计算.结合群论原理及分子的离解极限,分析了电子态势能曲线的特征,得出激发态B^1S^+对应的离解极限为H^++F^-(~1S).基于势能曲线,数值求解核运动的径向Schrodinge方程,得到J=0时束缚电子态X^1S^+,B^1S^+,C^1P和D^1S^+的振动能级和转动常数,继而进行数据拟合得到电子态的光谱常数,基态X^1S^+:ω_e=4146.94 cm^(-1),ω_ez_e=88.08 cm^(-1),B_e=21.22 cm^(-1),a=0.785 cm^(-1);B^1S^+态:ω_e=1131.37 cm^(-1),ω_ex_e=17.28 cm^(-1),B_e=3.96 cm^(-1),a_e=0.0215 cm^(-1),C^1P态:ω_e=2696.37 cm^(-1),ω_ex_e=73.43 cm^(-1),B_e=15.91 cm^(-1),a_e=0.776 cm^(-1),D^1S^+态:ω_e=3104.22 cm^(-1),ω_ex_e=118.92 cm^(-1),B_e=17.25 cm^(-1),a_e=0.992 cm^(-1),拟合结果与实验值吻合的较好.Potential energy curves （PECs） for the singlet and triplet low-lying electronic excited states of HF molecule have been calculated using the multi-reference configuration interaction （MRCI） method with the basis set of aug-cc-pVTZ where the Davidson correction was considered as approximation to full CI. The characteristics of these PECs are discussed by considering the group theory and molecular disso- ciation limits, and the ionic nature of the B1S＋ state is proved where the PEC tends to the H＋ ＋F- （1S） dissociation limit. Based on these PECs, the radial Schrt^dinge equations of nuclear motion are resolved and the vibrational levels and rotational constants for X~ S＋ , B~ S＋ , C^P and D~ S＋ states were obtained when the rotational quantum number J equals zero （J= 0）. Then the spectroscopic constants for these states were determined through spectral fitting method, for X1 S＋ w=4146.94 cm-1 , w.x = 88.07 cm-1, B1 = 21. 22 cm-1, a=0. 785 cm-1 for the first singlet electronic excited state B1 S＋： w = 1131.37 cm-1 , wx=17.28 cm-1 , B.=3.96 cm-1 , a,=0. 0215 cm-1 for CP：w.=2696.37 cm-1 ,w, x=73.43 cm-1,B,=15. 91 cm-1,a.=0. 776 cm-1 for D1S＋ .w.=3104.22 cm-1 , w.x,=llS. 92 cm-1, B.=17.25 cm-1,a.=0. 992 cm-1, all the calculation results are in good agreement with the experimen- tal values.

关 键 词：MRCI计算 电子激发态 势能曲线 光谱常数 HF分子 

分 类 号：O561[理学—原子与分子物理]