Investigations of spectroscopic parameters and molecular constants for X^1Σ_g^+, w^3△_u, and W^1△_u electronic states of P_2 molecule  

作　　者：Wang Jie-Min Feng Heng-Qiang Sun Jin-Feng Shi De-Heng 王杰敏;冯恒强;孙金锋;施徳恒(Department of Physics&Electronic Information,Luoyang Normal College,Luoyang 471022,China;College of Physics&Information Engineering,Henan Normal University,Xinxiang 453007,China)

机构地区：[1]Department of Physics&Electronic Information,Luoyang Normal College,Luoyang 471022,China [2]College of Physics&Information Engineering,Henan Normal University,Xinxiang 453007,China

出　　处：《Chinese Physics B》2012年第2期235-242,共8页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.10874064 and 60777012);the Program for Science and Technology Innovation Talents in Universities of Henan Province,China (Grant No.2010HASTIT022);the Program for Science & Technology of Henan Province,China (Grant No.092300410189)

摘　　要：The potential energy curves （PECs） of three low-lying electronic states （X1 ∑g^＋, w^3 △u, and W1 △u） of P2 molecule are investigated using the full valence complete active space self-consistent field （CASSCF） method followed by the highly accurate valence internally contracted multireference configuration interaction （MRCI） approach in conjunction with the correlation-consistent basis set in the valence range. The PECs of the electronic states involved are modified by the Davidson correction and extrapolated to the complete basis set （CBS） limit. With these PECs, the spectroscopic parameters of the three electronic states are determined and compared in detail with the experimental data. The comparison shows that excellent agreement exists between the present results and the available experimental data. The complete vibrational states are computed for the W3Au and WlAu electronic states when the rotational quantum number J equals zero and the vibrational level G（v）, the inertial rotation constant By, and the centrifugal distortion constant Dv of the first 30 vibrational states are reported, which accord well with the experimental data. The present results show that the two-point extrapolation scheme can obviously improve the quality of spectroscopic parameters and molecular constants.The potential energy curves （PECs） of three low-lying electronic states （X1 ∑g^＋, w^3 △u, and W1 △u） of P2 molecule are investigated using the full valence complete active space self-consistent field （CASSCF） method followed by the highly accurate valence internally contracted multireference configuration interaction （MRCI） approach in conjunction with the correlation-consistent basis set in the valence range. The PECs of the electronic states involved are modified by the Davidson correction and extrapolated to the complete basis set （CBS） limit. With these PECs, the spectroscopic parameters of the three electronic states are determined and compared in detail with the experimental data. The comparison shows that excellent agreement exists between the present results and the available experimental data. The complete vibrational states are computed for the W3Au and WlAu electronic states when the rotational quantum number J equals zero and the vibrational level G（v）, the inertial rotation constant By, and the centrifugal distortion constant Dv of the first 30 vibrational states are reported, which accord well with the experimental data. The present results show that the two-point extrapolation scheme can obviously improve the quality of spectroscopic parameters and molecular constants.

关 键 词：spectroscopic parameter molecular constant Davidson correction extrapolation 

分 类 号：O641.1[理学—物理化学]