Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (3): 431-438.doi: 10.3866/PKU.WHXB201401023

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Theory Studies on Low-Lying States of Lead Chalcogenide Cations

CAO Zhan-Li1, WANG Zhi-Fan2, YANG Ming-Li1, WANG Fan2   

  1. 1 Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, P. R. China;
    2 College of Chemistry, Sichuan University, Chengdu 610065, P. R. China
  • Received:2013-12-02 Revised:2013-12-31 Published:2014-02-27
  • Contact: WANG Fan E-mail:wangf44@gmail.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21273155).

Abstract:

In this work, we investigate the low-lying states of PbS, PbSe, and PbTe cations based on a recently developed equation-of-motion coupled-cluster approach for ionization potentials (EOMIP-CC) with spin-orbit coupling (SOC) at the CCSD level. Equilibrium bond lengths, harmonic frequencies as well as vertical and adiabatic ionization energies are calculated with EOMIP-SOC-CCSD and reasonable agreement with available experimental data is achieved. The contribution of triples is estimated by comparing results at the CCSD(T) level with those from EOMIP-CCSD when SOC is neglected. Better agreement with experimental data can be obtained if the contribution of triples is included. According to our results, the splitting between 2Π state is larger in PbTe+ than that in PbS+ and PbSe+, while coupling between 2Π1/2 and 2Σ1/2 owing to SOC is more significant in PbS+ and PbSe+. This is because the energy difference between 2Π and 2Σ+ states of PbTe+ is larger than that in PbS+ and PbSe+ and the SOC matrix element between 2Π1/2 and 2Σ1/2 states in PbTe+ is only half those in PbS+ and PbSe+. The present work presents new estimates on properties of these low-lying states and could serve as new references for future experiments.

Key words: Spin-orbit coupling, Equation-of-motion coupled-cluster approach, Ionization energy, Lead chalcogenide

MSC2000: 

  • O641