物理化学学报 >> 2012, Vol. 28 >> Issue (07): 1707-1713.doi: 10.3866/PKU.WHXB201205111

理论与计算化学 上一篇    下一篇

等电子三原子铀化物OUO2+、NUN和NUO+的结构和谐振频率的CCSD(T)计算研究

涂喆研1, 杨冬冬1, 王繁1, 李象远2   

  1. 1. 四川大学化学学院, 成都 610064;
    2. 四川大学化工学院, 成都 610065
  • 收稿日期:2012-03-15 修回日期:2012-05-11 发布日期:2012-06-07
  • 通讯作者: 王繁 E-mail:wangf@scu.edu.cn
  • 基金资助:

    国家自然科学基金(20973116)资助项目

A CCSD(T) Study on Structures and Harmonic Frequencies of the Isoelectronic Uranium Triatomic Species OUO2+, NUN and NUO+

TU Zhe-Yan1, YANG Dong-Dong1, WANG Fan1, LI Xiang-Yuan2   

  1. 1. College of Chemistry, Sichuan University, Chengdu 610064, P. R. China;
    2. College of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
  • Received:2012-03-15 Revised:2012-05-11 Published:2012-06-07
  • Contact: WANG Fan E-mail:wangf@scu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20973116).

摘要:

用小核相对论有效势和CCSD(T)方法计算了三原子铀化物OUO2+, NUN和NUO+的平衡键长和谐振频率. 计算结果显示U原子内层5s5p5d 电子相关能对这些化合物性质的影响非常小. 除NUN的弯曲振动频率,旋轨耦合效应对这些化合物的结构和频率的影响并不明显. 本文的计算结果与其他研究组的计算结果以及已有的实验值相比符合较好, 这表明作为单参考态方法, CCSD(T)能够对这些体系的键长和频率给出较精确的计算结果. 与此前密度泛函理论(DFT)的计算结果相比, CCSD(T)方法与PBE0泛函的结果吻合最好. 本文的工作有助于在用密度泛函方法研究这些体系时选择合适的交换相关泛函, 也为今后的实验研究提供了新的理论数据.

关键词: 铀化物, 耦合簇理论, 旋轨耦合

Abstract:

CCSD(T) calculations with small-core relativistic effective core potentials for equilibrium bond lengths and harmonic frequencies are presented for uranium triatomic OUO2+, NUN, and NUO+ species. The inner shell electron correlation of the U atom has almost no effect on the properties of these species, and the spin-orbit coupling only has a small effect, except in the bending mode of NUN. Our results agree reasonably well with previous theoretical results and the available experimental data, which indicates that the single-reference CCSD(T) method can be employed to study these species. Compared with previous results, the CCSD(T) results agree best with density functional theory (DFT) calculations performed using the PBE0 functional. The present work provides new estimates which are useful for future experimental work and for choosing proper exchange-correlation functionals in DFT calculations for these species.

Key words: Uranium species, Coupled cluster theory, Spin-orbit coupling

MSC2000: 

  • O641