The electronic structures of some extended conjugated electron acceptors within the Hartree-Fock approximation and beyond the mean-field approach as verified by the Hartree-Fock instabilities

Autor:	Michael C. Böhm, Helmut Vogler
Rok vydání:	1984
Předmět:	Chemistry Hartree–Fock method Electron symbols.namesake Mean field theory Atomic orbital Electron affinity Physics::Atomic and Molecular Clusters symbols Chiropractics Physical and Theoretical Chemistry Ionization energy Atomic physics Wave function Hamiltonian (quantum mechanics)
Zdroj:	Theoretica Chimica Acta
ISSN:	1432-2234 0040-5744
DOI:	10.1007/bf00577139
Popis:	The electronic structures of the extended conjugated electron acceptors1–3 were investigated within the framework of a semiempirical INDO and a π-electronic Hartree-Fock Hamiltonian. Utilizing Koopmans' theorem, predictions are made of the magnitude of the ionization potentials and the electron affinities and their dependence on the molecular geometry (“olefinic” vs. “aromatic”) and the nature of the acceptor functions. The validity of the Hartree-Fock approximation has been studied by means of the Thouless stability conditions. The INDO and π-SCF wave functions turn out to be adequate descriptions of the ground states of1–3. A single particle hole pair, due to a small energy separation between the highest occupied and lowest virtual orbital and a large Coulomb integral with respect to these orbitals leads to non-singlet (triplet) instabilities or near instabilities of the wave functions indicating the importance of spin correlation in1–3.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::530397542a44b6de11433f1afd87756a https://doi.org/10.1007/bf00577139 Zobrazit plný text záznamu Full text from SpringerLink