Ab initio calculations of the Ar-Ethane intermolecular potential energy surface using bond function basis sets

作者：Zhang, Jian-Dong^*; Li, Shu-Jin; Tao, Fu-Ming

来源：Journal of Computational Chemistry, 2013, 34(8): 673-680.

DOI：10.1002/jcc.23179

• argon
• ethane
• ab initio calculation
• molecular interaction
• bond functions

The intermolecular potential energy surface (PES) of argon with ethane has been studied by ab initio calculations at the levels of second-order MOllerPlesset perturbation (MP2) theory and coupled-cluster theory with single, double, and noniterative triple configurations (CCSD(T)) using a series of augmented correlation-consistent basis sets. Two sets of bond functions, bf1 (3s3p2d) and bf2 (6s6p4d2f), have been added to the basis sets to show a dramatic and systematic improvement in the convergence of the entire PES. The PES of Arethane is characterized by a global minimum at a near T-shaped configuration with a well depth of 0.611 kcal mol1, a second minimum at a collinear configuration with a well depth of 0.456 kcal mol1, and a saddle point connecting the two minima. It is shown that an augmented correlation-consistent basis set with a set of bond functions, either bf1 or bf2, can effectively produce results equivalent to the next larger augmented correlation-consistent basis set, that is, aug-cc-pVDZ-bf1 approximate to aug-cc-pVTZ, aug-cc-pVTZ-bf1 approximate to aug-cc-pVQZ. Very importantly, the use of bond functions improves the PES globally, resulting accurate potential anisotropy. Finally, MP2 method is inadequate for accurate calculations, because it gives a potentially overestimated well depth and, more seriously, a poor potential anisotropy.

• 出版日期2013-3-30
• 单位苏州大学