Unreliable description of dianions by using standard diffuse functions (6-31+G) with the RHF-LCAO method. The case of the relative stability of Y-shaped versus linear-conjugated dianions
✍ Scribed by Maurizio Guerra
- Book ID
- 103032968
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 670 KB
- Volume
- 197
- Category
- Article
- ISSN
- 0009-2614
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✦ Synopsis
The effect of the exponent of diffuse functions augmenting the 6-3 1 G split-valence basis set on the relative stability of Y-shaped versus linear conjugated dianions has been investigated within the restricted Hat-tree-Fock (RHF) approach. The use of standard diffuse functions in the ST0 6-3 1 + G basis set provides meaningless values of structural parameters, charge distribution, and Y/linear stability. Dianions are usually computed to lie energetically above the ground state of corresponding neutrals so the electron charge in the HOMO tends to be mainly localized at diffuse functions. This localization is influenced by the energy of the two highest MOs. The relative stability of structural isomeric dianions can be computed reliably without including diffuse functions in the basis set since addition of moderately diffuse functions does not affect its value significantly.