A new ab initio intermolecular potential energy surface and predicted rotational spectra of the Ar-H2S complex

作者：Lei Jinping; Zhou Yanzi; Xie Daiqian^*

来源：Journal of Chemical Physics, 2012, 136(8): 084310.

DOI：10.1063/1.3689443

• ab initio calculations
• argon
• bonds (chemical)
• coupled cluster calculations
• excited states
• ground states
• hydrogen compounds
• isomerism
• isotope effects
• potential energy functions
• potential energy surfaces
• rotational states
• rotational-vibrational states

We report a reliable three-dimensional ab initio intermolecular potential energy surface for the Ar-H2S complex with H2S monomer fixed at its experimental average structure. The potential energies were evaluated using the supermolecular approach at the coupled-cluster level with a large basis set including bond functions. The full counterpoise procedure was used to correct the basis set superposition error. The potential has a planar T-shaped global minimum with a well depth of 177.48 cm(-1) at the intermolecular distance of 3.72 angstrom. An additional planar local minimum is also found and is separated from the global minimum with an energy barrier with a height of 47.46 cm(-1). The combined radial discrete variable representation/angular finite basis representation method and the Lanczos algorithm were employed to calculate the rovibrational energy levels for three isotopic species of Ar-H2S complexes (Ar-(H2S)-S-32, Ar-(H2S)-S-33, and Ar-(H2S)-S-34). The rotational transition frequencies and structural parameters for the three isotopomers were also determined for the ground and the first excited states, which are all in good agreement with the available experimental values.

• 出版日期2012-2-28
• 单位南京大学