Interpretation of Open-Shell SCF Calculations on the T and V States of Ethylene
- Creators
- Basch, Harold
- McKoy, Vincent
Abstract
Self-consistent field calculations are reported on (planar and perpendicular geometric conformers of) the lowest energy triplet and singlet (pi,pi*) orbital configurations of ethylene, which are usually identified with the spectroscopic T and V states, respectively. For the planar conformation the calculation predicts a V state with the characteristics of a Rydberg state, but a T state of expected valence-shell character. The pi* orbital is much too large and the internuclear distance too small for the calculated V state, but are as expected for the T state. It is concluded that the calculated result for the supposed V state in the planar conformation is spurious due to the inadequacy of the Hartree–Fock single-configuration theory. The supposed V state here calculated may be identified with a Rydberg state which has been observed spectroscopically at ~ 1.4 eV higher energy than the V state in the optical spectrum. For the perpendicular conformation, the calculations yield resonable results for both the T and V states. Calculations also have been carried out on a singlet (sigma,pi*) state for planar ethylene; here the size of the pi* orbital is reasonable.
Additional Information
©1970 American Institute of Physics. Received 2 March 1970. The authors would like to thank Dr. M. Krauss, Dr. M.B. Robin, Dr. A.J. Merer, and Dr. K. Morokuma for useful and stimulating discussions. We would also like to thank Dr. M. Krauss, Dr. M.B. Robin, Dr. K. Morokuma, Dr. K.J. Miller, Dr. R. McDiarmid, Dr. D. Neumann, and Dr. J.L. Whitten for access to their work prior to publication. The comments of the referees were very helpful and these are gratefully acknowledged.Attached Files
Published - BASjcp70.pdf
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Additional details
- Eprint ID
- 11140
- Resolver ID
- CaltechAUTHORS:BASjcp70
- Created
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2008-07-17Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field