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A potential energy surface for the electronic ground state of CO 2
Author(s) -
Lu Yuhui,
Xie Daiqian,
Yan Guosen
Publication year - 2000
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(2000)78:4<269::aid-qua9>3.0.co;2-w
Subject(s) - rotational–vibrational spectroscopy , potential energy surface , hitran , hamiltonian (control theory) , chemistry , ab initio , potential energy , atomic physics , ground state , bond length , physics , quantum mechanics , molecule , excited state , spectroscopy , mathematics , mathematical optimization , organic chemistry
The potential energy surface for the electronic ground state of CO 2 is refined by means of a two‐step variational procedure using the exact rovibrational Hamiltonian in the bond length–bond angle coordinates. In the refinement, the observed rovibrational energy levels for J =0–4 below 16,000 cm −1 , obtained from the effective spectroscopic constants of CO 2 given by Rothman et al. (J Quant Spectrosc Radiat Transfer 1992, 48, 537) in the HITRAN data base, are used as the input data points. The accurate ab initio force constants of Martin et al. (Chem Phys Lett 1993, 205, 535) are taken as the initial guess for the potential. The root‐mean‐square error of this fit to the 431 observed rovibrational energy levels is 0.05 cm −1 . With the optimized potential energy surface, we also calculate the rovibrational energy levels of 13 C 16 O 2 and 12 C 18 O 2 . The results are in good agreement with experimental data. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 78: 269–280, 2000