Performance of the VBSCF method for pericyclic and π bond shift reactions. Issue 10 (27th December 2018)

• Record Type: Journal Article
• Authors: Zhang, Huaiyu; Zhou, Chen; Mo, Yirong; Wu, Wei
• Other Names: Mo Yirong guestEditor.; Wu Wei guestEditor.; Cao Zexing guestEditor.
• Is Part Of: Journal of computational chemistry. Volume 40:Issue 10(2019)
• Page Start: 1123
• Page End: 1129
• Publication Date: 2018-12-27
• Subjects: valence bond self‐consistent field -- benchmark -- reaction energies -- activation barriers; Chemistry -- Data processing -- Periodicals; 542.85
• DOI: 10.1002/jcc.25729
• Languages: English
• ISSNs: 0192-8651

Abstract

Abstract : The performance of the valence bond self‐consistent field (VBSCF) method was investigated in this paper by predicting the activation barriers and reaction energies in pericyclic and π bond shift reactions for hydrocarbons. The benchmarking set includes 3 electrocyclic reactions, 3 sigmatropic shifts, 3 cycloadditions, 2 cycloreversions, and 7 π bond shift reactions, where the first 11 reactions are taken from Houk's standard set ( J. Phys. Chem. A 2003, 107, 11445). Computational results reveal that the VB(CI) method, which performs VBSCF calculations first with full covalent structures and then includes all mono‐ and di‐ionic structures to compute the total energy without further orbital optimization, matches the accuracy of the complete active space SCF (CASSCF) method very well. The mean absolute error values (the deviations from the CASSCF data) are 0.01 kcal/mol for the reaction energy, and 0.26 and 0.32 kcal/mol for the activation energy with the 6‐31G and 6‐31G(d) basis sets, respectively. © 2018 Wiley Periodicals, Inc. Abstract : The performance of the valence bond self‐consistent field (VBSCF) method in active spaces ranging from (4e, 4o) to (20e, 20o) was investigated by predicting the activation barriers and reaction energies. Computational results reveal that the VB(CI) method, which performs VBSCF calculations first with full covalent structures and then with all mono‐ and di‐ionic structures to compute the total energy without further orbital optimizations, matches the accuracy of CASSCF very well.