中国物理B ›› 2015, Vol. 24 ›› Issue (1): 13101-013101.doi: 10.1088/1674-1056/24/1/013101

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Accurate ab initio-based analytical potential energy function for S21Δg) via extrapolation to the complete basis set limit

张路路, 高守宝, 孟庆田, 宋玉志   

  1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, China
  • 收稿日期:2014-07-11 修回日期:2014-08-08 出版日期:2015-01-05 发布日期:2015-01-05
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11304185 and 11074151).

Accurate ab initio-based analytical potential energy function for S21Δg) via extrapolation to the complete basis set limit

Zhang Lu-Lu (张路路), Gao Shou-Bao (高守宝), Meng Qing-Tian (孟庆田), Song Yu-Zhi (宋玉志)   

  1. College of Physics and Electronics, Shandong Normal University, Jinan 250014, China
  • Received:2014-07-11 Revised:2014-08-08 Online:2015-01-05 Published:2015-01-05
  • Contact: Song Yu-Zhi E-mail:yzsong@sdnu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11304185 and 11074151).

摘要:

The potential energy curves (PECs) of the first electronic excited state of S21Δg) are calculated employing a multi-reference configuration interaction method with the Davidson correction in combination with a series of correlation-consistent basis sets from Dunning: aug-cc-pVXZ (X=T, Q, 5, 6). In order to obtain PECs with high accuracy, PECs calculated with aug-cc-pV(Q, 5)Z basis sets are extrapolated to the complete basis set limit. The resulting PECs are then fitted to the analytical potential energy function (APEF) using the extended Hartree-Fock approximate correlation energy method. By utilizing the fitted APEF, accurate and reliable spectroscopic parameters are obtained, which are consistent with both experimental and theoretical results. By solving the Schrödinger equation numerically with the APEFs obtained at the AV6Z and the extrapolated AV(Q, 5)Z level of theory, we calculate the complete set of vibrational levels, classical turning points, inertial rotation and centrifugal distortion constants.

关键词: multi-reference configuration interaction method (MRCI), analytical potential energy functions, vibrational levels, spectroscopic parameters

Abstract:

The potential energy curves (PECs) of the first electronic excited state of S21Δg) are calculated employing a multi-reference configuration interaction method with the Davidson correction in combination with a series of correlation-consistent basis sets from Dunning: aug-cc-pVXZ (X=T, Q, 5, 6). In order to obtain PECs with high accuracy, PECs calculated with aug-cc-pV(Q, 5)Z basis sets are extrapolated to the complete basis set limit. The resulting PECs are then fitted to the analytical potential energy function (APEF) using the extended Hartree-Fock approximate correlation energy method. By utilizing the fitted APEF, accurate and reliable spectroscopic parameters are obtained, which are consistent with both experimental and theoretical results. By solving the Schrödinger equation numerically with the APEFs obtained at the AV6Z and the extrapolated AV(Q, 5)Z level of theory, we calculate the complete set of vibrational levels, classical turning points, inertial rotation and centrifugal distortion constants.

Key words: multi-reference configuration interaction method (MRCI), analytical potential energy functions, vibrational levels, spectroscopic parameters

中图分类号:  (Ab initio calculations)

  • 31.15.A-
34.20.Cf (Interatomic potentials and forces) 31.50.Df (Potential energy surfaces for excited electronic states) 33.20.-t (Molecular spectra)