物理化学学报 >> 2001, Vol. 17 >> Issue (06): 501-506.doi: 10.3866/PKU.WHXB20010606

研究论文 上一篇    下一篇

CO2二聚体分子弱结合作用的DFT计算

薛卫东;张广丰;朱正和;汪小琳;罗德礼;邹乐西;孙颖   

  1. 四川大学原子与分子物理研究所,成都 610065;中国工程物理研究院,绵阳 621900;四川师范大学,成都 610066
  • 收稿日期:2000-12-25 修回日期:2001-02-05 发布日期:2001-06-15
  • 通讯作者: 薛卫东 E-mail:xiesh@swufe.edu.cn

Calculation on Weakly Bound Carbon Dioxide Dimer by DFT

Xue Wei-Dong;Zhang Guang-Feng;Zhu Zheng-He;Wang Xiao-Lin;Luo De-Li;Zou Le-Xi;Sun Ying   

  1. Atomic and Molecular Physical Institute,Sichuan University,Chengdu 610065; China Academy of Engineering Physics,Mianyang 612900;Sichuan Normal University,Chengdu 610066
  • Received:2000-12-25 Revised:2001-02-05 Published:2001-06-15
  • Contact: Xue Wei-Dong E-mail:xiesh@swufe.edu.cn

摘要: 用密度泛函理论(DFT)的Becke 3LYP方法,在不同基集合(631G和6311G系列)下对平行结构(C 2h)和T形结构(C2v)的CO2二聚体进行ab initio计算.通过计算,得到了CO2二聚体C2h和C2v两种构型的结构参数和离解能,并给出了CO2二聚体相对稳定构型C2h的12个正则振动分析图.结果表明,CO2二聚体的离解能为2 kJ•mol-1,CO2分子之间振动频率很小,从而说明CO2二聚体是弱结合分子.

关键词: CO2二聚体, 密度泛函理论, 弱结合分子

Abstract: It is predicted that there are two geometrical configurations of the slipped parallel (C2h) and T shaped (C2v) carbon dioxide dimer using the density functional theory(DFT) with basis sets 631G or 6311G.The normal vibration analysis has showed 12 vibrational modes for C2h,which can be classified in three types ,i.e.ν11(bu),ν1(ag),ν9(bu)and ν4(ag) contributed mainly by intramolecular stretching vibrations,ν8(bg),ν12(bu),ν6(au) and ν5(ag) contributed mainly by intramolecular bending vibrations,and ν7(au),ν10(bu), ν2(ag) and ν3(ag) provided by intermolecular vibrations with frequencies 20~100 cm-1.The (CO2)2 is a typical weakly bound molecule based on its small dissociation energy 2 kJ•mol-1 and normal vibration modes.

Key words: Carbon dioxide dimer, Density functional theory(DFT), Weakly bound molecule