中国物理B ›› 2012, Vol. 21 ›› Issue (8): 83104-083104.doi: 10.1088/1674-1056/21/8/083104

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

An ab initio investigation of the low-lying electronic states of BeH

董嫣然, 张树东, 侯圣伟, 程起元   

  1. Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, Department of Physics, Qufu Normal University, Qufu 273165, China
  • 收稿日期:2011-12-22 修回日期:2012-02-15 出版日期:2012-07-01 发布日期:2012-07-01

An ab initio investigation of the low-lying electronic states of BeH

Dong Yan-Ran (董嫣然), Zhang Shu-Dong (张树东), Hou Sheng-Wei (侯圣伟), Cheng Qi-Yuan (程起元 )   

  1. Shandong Provincial Key Laboratory of Laser Polarization and Information Technology, Department of Physics, Qufu Normal University, Qufu 273165, China
  • Received:2011-12-22 Revised:2012-02-15 Online:2012-07-01 Published:2012-07-01
  • Contact: Zhang Shu-Dong E-mail:zhangsd2@126.com

摘要: Potential energy curves (PECs) for the ground state (X2Σ+) and the four excited electronic states (A2Π, B2Π, C2Σ+, 4Π) of BeH molecule are calculated using the multi-configuration reference single and double excited configuration interaction (MRCI) approach in combination with the aug-cc-pVTZ basis sets. The calculation covers the internuclear distance ranging from 0.07 nm to 0.70 nm, and the equilibrium bond length Re and the vertical excited energy Te are determined directly. It is evident that the X2Σ+, A2Π, B2Π, C2Σ+ states are bound and 4Π is a repulsive excited state. With the potentials, all of the vibrational levels and inertial rotation constants are predicted when the rotational quantum number J is set to be equal to zero (J = 0) by numerically solving the radial Schrödinger equation of nuclear motion. Then the spectroscopic data are obtained including the rotation coupling constant ωe, the anharmonic constant ωexe, the equilibrium rotation constant Be and the vibration–rotation coupling constant αe. These values are compared with theoretical and experimental results currently available, showing that they are in agreement with each other.

关键词: multi-configuration reference single and double excited configuration interaction method, BeH potential curves, vibrational levels, spectroscopic constants

Abstract: Potential energy curves (PECs) for the ground state (X2Σ+) and the four excited electronic states (A2Π, B2Π, C2Σ+, 4Π) of BeH molecule are calculated using the multi-configuration reference single and double excited configuration interaction (MRCI) approach in combination with the aug-cc-pVTZ basis sets. The calculation covers the internuclear distance ranging from 0.07 nm to 0.70 nm, and the equilibrium bond length Re and the vertical excited energy Te are determined directly. It is evident that the X2Σ+, A2Π, B2Π, C2Σ+ states are bound and 4Π is a repulsive excited state. With the potentials, all of the vibrational levels and inertial rotation constants are predicted when the rotational quantum number J is set to be equal to zero (J = 0) by numerically solving the radial Schrödinger equation of nuclear motion. Then the spectroscopic data are obtained including the rotation coupling constant ωe, the anharmonic constant ωexe, the equilibrium rotation constant Be and the vibration–rotation coupling constant αe. These values are compared with theoretical and experimental results currently available, showing that they are in agreement with each other.

Key words: multi-configuration reference single and double excited configuration interaction method, BeH potential curves, vibrational levels, spectroscopic constants

中图分类号:  (Potential energy surfaces for ground electronic states)

  • 31.50.Bc
31.50.Df (Potential energy surfaces for excited electronic states) 31.15.vn (Electron correlation calculations for diatomic molecules)