MP2 or B3LYP: computed bond distances compared with CCSD(T)/cc-pVQZ

作者：Chong Delano P^*

来源：Canadian Journal of Chemistry, 2018, 96(3): 336-339.

DOI：10.1139/cjc-2017-0651

• bond lengths
• CCSD(T)
• CCSD
• MP3
• MP2
• HF
• B3LYP

The equilibrium bond lengths of 41 small molecules are calculated by Gaussian09 and ADF2013 programs. We use five different basis sets: 6-31G*, cc-pVDZ, 6-311G+(2d, p), cc-pVTZ, and cc-pVQZ, for six different methods: Hartree-Fock, MP2, MP3, CCSD, CCSD(T), and B3LYP. The reliability of each level of theory on 89 bond lengths compared with CCSD(T)/cc-pVQZ is examined in terms of the mean absolute deviation. In particular, basis set dependence of the relative reliability of the two popular methods MP2 versus B3LYP is important to computational chemists. In addition, the efficient even-tempered basis set of Slater-type orbital called et-pVQZ, available in the ADF2013 program, is tested with the popular density functional B3LYP.

• 出版日期2018-3