物理化学学报 >> 2005, Vol. 21 >> Issue (06): 658-662.doi: 10.3866/PKU.WHXB20050616

研究论文 上一篇    下一篇

BH分子X 1Σ+A 1ΠB 1Σ+ 态的势能函数

谢安东; 施德恒; 朱遵略; 朱正和   

  1. 四川大学原子与分子物理研究所,成都 610065; 井冈山学院物理系,江西 吉安 343009;空军第一航空学院基础部,河南 信阳 464000
  • 收稿日期:2004-11-04 修回日期:2005-02-02 发布日期:2005-06-15
  • 通讯作者: 朱正和 E-mail:zhuxm@scu.edu.cn

Analytical Potential Energy Functions for the Electronic States X 1Σ+, A 1Π and B 1Σ+ of BH Molecule

XIE An-dong; SHI De-heng; ZHU Zun-lue; ZHU Zheng-he   

  1. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065; Department of Physics, College of Jinggangshan, Ji′an 343009; Department of Foundation, The First Aeronautical College of Air Force, Xinyang 464000
  • Received:2004-11-04 Revised:2005-02-02 Published:2005-06-15
  • Contact: ZHU Zheng-he E-mail:zhuxm@scu.edu.cn

摘要: 利用SAC/SAC-CI方法,使用D95++、6-311++g及cc-PVTZ等基组,对BH分子的基态(X 1Σ+)、第一简并激发态(A 1Π)及第二激发态(B 1Σ+)的平衡结构和谐振频率进行了优化计算. 通过对三个基组计算结果的比较,得出了cc-PVTZ基组为三个基组中的最优基组的结论;使用cc-PVTZ基组,利用SAC的GSUM(group sum of operators)方法对基态(X 1Σ+), SAC-CI的GSUM方法对激发态(A 1ΠB 1Σ+)进行单点能扫描计算, 用正规方程组拟合Murrell-Sorbie函数,得到了相应电子态的完整势能函数;从得到的势能函数计算了与基态(X 1Σ+)、第一简并的激发态(A 1Π)和第二激发态(X 1Σ+)相对应的光谱常数(Be、αe、ωe 和ωeχe),结果与实验数据较为一致. 其中基态、第一激发态与实验数据吻合得较好.

关键词: 原子与分子物理, 分子结构与势能函数, BH, 激发态, Murrell-Sorbie函数

Abstract: The energies, equilibrium geometries and harmonic frequencies of three electronic states (the ground state X 1Σ+, the first degenerate state A 1Π and the second state B 1Σ+)of BH molecule have been calculated using the GSUM (group sum of operators) method of SAC/ SAC-CI with the basis sets D95++, 6-311++g and cc-PVTZ. Comparing among the above mentioned three basis sets, the conclusion is gained that the basis set cc-PVTZ is the most suitable for the energy calculation of BH molecule. The whole potential curves for these three electronic states are further scanned using SAC/cc-PVTZ method for the ground state and SAC-CI/cc-PVTZ methods for the excited states, then having a least square fitting to Murrell-Sorbie function, and last the spectroscopy constants (Be, αe, ωe, andωeχe) are calculated, which are in better agreement with the experimental data. It is believed that Murrell-Sorbie function form and SAC/ SAC-CI method are suitable not only for the ground state, but for the low-lying excited states as well.

Key words: Atomic and molecular physics, Molecular structure and potential function, BH, Excited state, Murrell-Sorbie function