MULTICONFIGURATION WAVEFUNCTIONS FOR THE $\Pi$-ELECTRON STATES OF ETHYLENE
View/ Open
Creators:
Bender, Charles F.Dunning, T. H., Jr.
Goddard, W. A., III
Hunt, W. J.
Noyes, Arthur A.
Schaefer, H. F., III
Issue Date:
1972Metadata
Show full item recordPublisher:
Ohio State UniversityAbstract:
Ab initio calculations have been carried out on the $N(\Pi^{2})$, $T(\Pi \Pi^{*})$ and $V(\Pi \Pi^{*})$ states of ethylene in a planar nuclear configuration. A ``double zeta’’ gaussian basis, augmented by diffuse functions, was used. A wide variety of configuration interaction wavefunctions (including as many as 1605 configurations), optimized by the iterative natural orbital method, were computed. The calculations predict vertical excitation energies of $\sim 4.2$ eV for the $T(\Pi \Pi^{*})$ state and $\sim 8.1$ eV for the $V(\Pi \Pi^{*})$ state. The spatial extent of the ground and excited triplet states is that of a normal valence state with $\langle x^{2} \rangle \sim 12$ $bohr^{2} $. The excited singlet state, on the other hand, is found to be quite diffuse or Rydberg-like, $\langle x^{2} \rangle \sim 35 bohr^{2}$; electron correlation decreases $\langle x^{2} \rangle$ by 30\% from the Hartree-Fock value (52 $bohr^{2}$).
Description:
Author Institution: Lawrence Livermore Laboratory; Laboratory of Chemical Physics, California Institute of Technology; Department of Chemistry, University of California Berkley
Type:
articleOther Identifiers:
1972-Y-3Items in Knowledge Bank are protected by copyright, with all rights reserved, unless otherwise indicated.