An efficient approximation in the multiconfigurational self-consistent field (MC SCF) method is presented for calculations on large systems. In this method, the orbitals are spanned by adequate orthonormal orbitals, such as Hartree-Fock orbitals, instead of by the entire set of basis functions, and
Improved virtual orbitals in the potential of the SCF ion
β Scribed by K. Hirao; S. Huzinaga
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- English
- Weight
- 269 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
β¦ Synopsis
We show that if excited states are to be calculated in the improved virtual orbital approach, it would be better to generate the virtual orbitals in the potential of the SCF ion rather than the Koopmans' theorem ion.
π SIMILAR VOLUMES
The oxoborate ion BO-has been investigated at Ihe MC SCF fevel of approximation. using an augmented double-zeta tx~.&-Potenti me3 have been calculated for the three lowest stales. The results are compared to those ohtamed for 80 in a previous, simhu study.
A computational procedure for generating space-symmetry-adapted ## Ε½ . Bloch functions BF is presented. The case is discussed when BF are built from a basis of Ε½ w x. local functions atomic orbitals AOs . The method, which is completely general in the sense that it applies to any space group and
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