Favorable performance of the DFT methods in predicting the minimum-energy structure of the lowest triplet state of WF4
✍ Scribed by Maciej Gutowski
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 172 KB
- Volume
- 73
- Category
- Article
- ISSN
- 0020-7608
No coin nor oath required. For personal study only.
✦ Synopsis
The tetrahedral structure of the lowest triplet state of the WF complex 4 Ž . was examined using different variants of the density functional theory DFT and conventional ab initio methods. The low-level, conventional, ab initio methods, such as SCF, MP2, MP3, and CISD, predict the tetrahedral structure to be a minimum, whereas the DFT schemes predict an imaginary frequency for the e vibrational mode. Only after recovering electron correlation effects at the MP4 and higher levels, the conventional electronic structure methods also predict the T structure to be a second-order stationary d point. This is not the correlation but the exchange part of the DFT functionals which is responsible for the discrepancy between the DFT and low-level, conventional, ab initio predictions. The lowering of symmetry to C leads to a minimum on the lowest triplet 2 v potential energy surface and the electronic energy difference between the T and C d 2 v * On leave from the