An accurate three-dimensional potential energy surface for the He-Na2 complex

• 来源期刊: 中国科学B辑（英文版）
• 年，卷（期）: 2008,（6）
• 页码范围: 539-544
• 页数: 6页
• 语种: 英文
• DOI: 10.1007/s11426-008-0019-2

摘要

An accurate three-dimensional potential energy surface (PES) for the He-Na2 van der Waals complex was calculated at the coupled cluster singles-and-doubles with noniterative inclusion of connected triple (CCSD(T)) level of theory. A mixed basis set, aug-cc-pVQZ for the He atom and cc-pCVQZ for the sodium atom, and an additional (3s3p2dlf) set of midbond functions were used. The computed inter-action energies in 819 configurations were fitted to a 96-parameter analytic potential model by least squares fitting. The PES has two shallow wells corresponding to the T-shaped structure and the linear configuration, which are located at 12.5a0 and 14 a0 with depths of 1.769 and 1.684 cm-1, respectively. The whole potential energy surface exhibits weak anisotropy. Based on the fitted PES, state-to-state differential cross sections were calculated.