TY - JOUR
T1 - Extended Hartree-Fock (EHF) theory of chemical reactions VI
T2 - Hybrid DFT and post-Hartree-Fock approaches for concerted and non-concerted transitions structures of the Diels-Alder reaction
AU - Isobe, H.
AU - Takano, Y.
AU - Kitagawa, Y.
AU - Kawakami, T.
AU - Yamanaka, S.
AU - Yamaguchi, K.
AU - Houk, K. N.
N1 - Funding Information:
This work has been supported by a Grant-in-Aid for Scientific Research on Priority Areas (No. 10149105 'Metal Assembled Complexes') from the Ministry of Education, Science, Sports and Culture, Japan. Y.T. was also supported by Research Fellowships of the Japan Society for the Promotion of Science for Young Scientists.
PY - 2002/3/20
Y1 - 2002/3/20
N2 - Activation barrier heights for concerted and non-concerted transition structures between butadiene and ethylene have been calculated by the broken-symmetry Hartree-Fock (HF), QCISD(T), and CCSD(T) methods with and without approximate spin projection, and the spin-restricted CASCI, CASSCF UNO MP2 and MR MP2 methods. They also have been calculated by the density functional theory (DFT) and hybrid DFT (HDFT) methods such as B2LYP and B3LYP. The reliability and utility of the HDFT methods have been investigated, and compared with the post-HF and MR MP2 results. The information entropy and related electron correlation indices also have been examined in relation to the polyradical character of the transition structures. Implications of the present results are discussed concerning the applicability of HDFT to large systems.
AB - Activation barrier heights for concerted and non-concerted transition structures between butadiene and ethylene have been calculated by the broken-symmetry Hartree-Fock (HF), QCISD(T), and CCSD(T) methods with and without approximate spin projection, and the spin-restricted CASCI, CASSCF UNO MP2 and MR MP2 methods. They also have been calculated by the density functional theory (DFT) and hybrid DFT (HDFT) methods such as B2LYP and B3LYP. The reliability and utility of the HDFT methods have been investigated, and compared with the post-HF and MR MP2 results. The information entropy and related electron correlation indices also have been examined in relation to the polyradical character of the transition structures. Implications of the present results are discussed concerning the applicability of HDFT to large systems.
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U2 - 10.1080/00268970110092375
DO - 10.1080/00268970110092375
M3 - Article
AN - SCOPUS:0037139847
VL - 100
SP - 717
EP - 727
JO - Molecular Physics
JF - Molecular Physics
SN - 0026-8976
IS - 6
ER -