## Abstract The spin projected extended Hartree‐Fock equations for successive optimization of the orbitals are derived for the four‐electron case and applied to butadiene in the PPP approximation. The method shows an excellent convergence and gives 91.4% of the correlation energy for the given mode
Spin-projected EHF method. III. Applications to π-electron systems
✍ Scribed by I. Mayer; M. Kertész
- Book ID
- 104578652
- Publisher
- John Wiley and Sons
- Year
- 1975
- Tongue
- English
- Weight
- 462 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0020-7608
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✦ Synopsis
Abstract
The surely convergent procedure to obtain extended Hartree–Fock (EHF) solutions of the spin‐projected scheme, for which the equations are given in Part II, is applied to eleven π‐electronic systems with 2–10 electrons at the PPP level of integral approximations. The method takes into account a considerable part of the correlation energy. The symmetry properties of the EHF wave functions obtained are discussed together with some computational details. A simplified algorithm is also described.
📜 SIMILAR VOLUMES
A srmphtied method to calculate the excitation spectra of n-electron systems is proposed. The method is based on the assumptton that a "cluster" approxrmation can be apphed to exctted states. It is demonstrated that. for the low-lying triplet and opttcally allowed states of butadtene, hexatriene and
## Abstract In this paper, the symmetrized basis function method is extended and used for the classification of the total spin states of many‐electron systems. The reduction matrix, which is expressed as a series of products and direct products of matrices is derived. It is very advantageous that t