TY - JOUR
T1 - Ab initio UHF and UHF NO CI approaches for quasi-degenerate systems
T2 - methylene peroxide (CH2OO)
AU - Yamaguchi, K.
AU - Yabushita, S.
AU - Fueno, T.
AU - Kato, S.
AU - Morokuma, K.
AU - Iwata, S.
PY - 1980/5/1
Y1 - 1980/5/1
N2 - The ab initio UHF and multi-reference (MR) UHF natural-orbital (NO) CI methods have been applied to elucidate geometrical structures and electronic energy levels of methylene peroxide which is regarded as a typical example of a quasidegenerate system. The results by MR UHF NO CI are in good agreement with those of the GVB CI method. It is shown that the present CI is closely related to the extended Hartree-Fock CI approach, which is equivalent to the GVB CI or MC SCF CI for diradical species.
AB - The ab initio UHF and multi-reference (MR) UHF natural-orbital (NO) CI methods have been applied to elucidate geometrical structures and electronic energy levels of methylene peroxide which is regarded as a typical example of a quasidegenerate system. The results by MR UHF NO CI are in good agreement with those of the GVB CI method. It is shown that the present CI is closely related to the extended Hartree-Fock CI approach, which is equivalent to the GVB CI or MC SCF CI for diradical species.
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U2 - 10.1016/0009-2614(80)80224-7
DO - 10.1016/0009-2614(80)80224-7
M3 - Article
AN - SCOPUS:0000833574
SN - 0009-2614
VL - 71
SP - 563
EP - 568
JO - Chemical Physics Letters
JF - Chemical Physics Letters
IS - 3
ER -