ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Using the method of alternant molecular orbitals (AMO), it is shown that the energies of AMOS (Ekσ) for an arbitrary heteronuclear alternant system, having a singlet ground state, are connected with the energies of MOS (ek(k)) obtained by means of the conventional Hartree-Fock (HF) method (SCF-LCAO-MO-PPP) via the formula: \documentclass{article}\pagestyle{empty}\begin{document}$$ E_{k\sigma } = {\raise0.7ex\hbox{$1$} \!\mathord{\left/ {\vphantom {1 2}}\right.\kern-\nulldelimiterspace} \!\lower0.7ex\hbox{$2$}}\left( {e_k + e_{\bar k} + \delta _{1,k\sigma } } \right) \pm \sqrt {\left( {\frac{{e_k - e_{\bar k} }}{2} + \delta _{2,k\sigma } } \right)^2 + \delta _{3,k\sigma }^2 } $$\end{document} In the general case, the determination of the correlation corrections δi,kσ is connected with the solving of a complicated system of integral equations, which is considerably simplified if the Hubbard approximation is accepted for the electron interaction.The energy spectrum of a chain with two atoms in the elementary cell (AB)n is considered as an example. It is shown that if nontrivial solutions exist (δi,kσ ≠ 0), the correlation correction for AMOS of different spin are different (δi,kσ ≠ δi,kβ), from which it follows, that the width of the energy gap ΔE∞ for AMOS with different spin is different: ΔE∞,α ≠ ΔE∞,β.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560130314
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