Acta Chim. Sinica ›› 2018, Vol. 76 ›› Issue (2): 138-142.DOI: 10.6023/A17070347 Previous Articles    

Article

复合物Kr-CS2的一个新的四维的势能面及其红外光谱的预测

洪琪a, 秦淼a, 朱华a,b   

  1. a 四川大学化学学院 成都 610064;
    b 四川大学生物治疗国家重点实验室 成都 610064
  • 投稿日期:2017-09-08 发布日期:2017-11-06
  • 通讯作者: 朱华 E-mail:zhuhua@scu.edu.cn
  • 基金资助:

    国家自然科学基金(No.21373139)资助项目.

A New Four-Dimensional Potential Energy Surface and Predicted Infrared Spectra for the Kr-CS2 Complex

Hong Qia, Qin Miaoa, Zhu Huaa,b   

  1. a College of Chemistry, Sichuan University, Chengdu 610064;
    b State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610064
  • Received:2017-09-08 Published:2017-11-06
  • Contact: 10.6023/A17070347 E-mail:zhuhua@scu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21373139).

The spectra of the van der Waals (vdW) complexes provide useful information on the intermolecular potential energy surfaces (PESs) and dynamics of such weakly bound molecules. First and foremost, an accurate potential energy surface is required to allow for spectroscopic analysis for van der Waals complexes. Thus, constructing an effective reduced-dimension potential energy surface, which includes direct relevant intramolecular modes, is the most feasible way and widely used in the recent potential studies. In this work, we present a four-dimensional (4D) ab initio potential energy surface (PES) of the Kr-CS2 complex at the coupled-cluster singles and doubles with noniterative inclusion of connected triples[CCSD(T)]-F12 level. We employed the aug-cc-pVTZ basis set of Woon and Dunning for the C and S atoms and the aug-cc-pVTZ-PP basis set for Kr. The bond functions (3s3p2d1f1g) (for 3s and 3p, α=0.9, 0.3, 0.1; for 2d, α=0.6, 0.2; for f and g, α=0.3) were placed at the mid-point of the R vector. The Q1 and Q3 normal modes for the ν1 symmetric stretching vibration and ν3 antisymmetric stretching vibration of CS2 were explicitly taken into account in the calculations of the Kr-CS2 potential energies. Two vibrationally averaged potentials with CS2 at both the vibrational ground and the ν1+ν3 excited states were generated from the integration of the four-dimensional potential over the Q1 and Q3 coordinates. Each potential contains a T-shaped global minimum and two equivalent linear local minima. These fits to 9000 points have root-mean-square (rms) deviations of 0.143 and 0.145 cm-1 for the ground and the ν13 excited states, respectively. The radial discrete variable representation (DVR)/angular finite basis representation (FBR) method and Lanczos algorithm were employed to calculate the rovibrational states without separating the inter-and intra-molecular vibrations. The spectroscopic parameters for the ground and the ν13 excited states of Kr-CS2 are predicted. In addition, the predicted band origin shift is -1.2357 cm-1 for Kr-CS2.

Key words: Kr-CS2, ab initio, potential energy surface, infrared spectra