It is shown that the conventional concepts based on the use of the HOMO and LUMO are founded on very questionable assumptions. In particular, it is shown both theoretically and computationally that the LUMO of almost all neutral atoms and molecules is a continuum function with energy zero. The LUMO
Modification of virtual orbitals
โ Scribed by Nelson H. F. Beebe
- Publisher
- John Wiley and Sons
- Year
- 1979
- Tongue
- English
- Weight
- 663 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0020-7608
No coin nor oath required. For personal study only.
โฆ Synopsis
Abstract
The utility of modifying the virtual orbitals of the Fock operator by introducition of an additional potential is discussed. A particularly convenient form for computational implementations is obtained, and improved methods for the practical solution of the secular problem are recommended.
๐ SIMILAR VOLUMES
## Abstract The application of the MBPT in the localized representation requires that both the occupied and the virtual orbitals obtained by the canonical HF equation should be localized. The localization of the occupied orbitals is straightforward in general by any localization method. It is shown
The goal of obtaining accurate potential energy surfaces for the study of intermolecular forces is of fundamental importance. In this article, we propose a new method to generate a set of virtual orbitals optimized in such a way to give very compact valence bond (VB) wave functions with the same acc
A modified Fock operator, having "virtual" eigenvalues and eigenvtctors closely resemblinp one-electron excitations, is derived from a variational method for excited states. A numerical illustration on the tie atom is given. The question of the s\*called virtual orbit& in the Hartree-Fock method ha
The efficiency of modified virtual orbitals (MVO) of ionic type and of approximate orthogonalized natural orbitals (ONO) in the CI-SD calculations was studied for 0, and SO, molecules and compared with the commonly used canonical virtual orbitals (CVOs). The systems studied represent a class of elec