Abstract
Plots of the pseudopotentials, valence orbitals and their differences for FSGO, large-basis Hartree-Fock-Roothaan and pseudopotential calculations on Li2 are presented. In agreement with earlier arguments, it is concluded that the success of the FSGO procedure depends upon a balanced description of core and valence orbitals. If the description of the core is improved compared to the simple FSGO single-Gaussian characterization, the use of simple FSGO for the valence density is not well attuned to the (more structured) core, and poor results are obtained. Conversely, a proper FSGO pseudopotential yields highly satisfactory FSGO valence orbitals, but is not successful if applied in a large-basis ab initio calculation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 324-334 |
| Number of pages | 11 |
| Journal | Journal of the Chemical Society, Faraday Transactions 2: Molecular and Chemical Physics |
| Volume | 74 |
| DOIs | |
| State | Published - 1978 |
Funding
Perhaps the most surprising result of the present work is the great sensitivity of both the subminimal basis FSGO calculation and the large-basis HFR to fine details of the pseudopotential : qualitatively, HFR and FSGO pseudopotentials are similar, but they yield different results in either valence-only calculations. This conclusion, which was already clear from the poor results yielded by many previous pseudo- potential calculations, points out once again the necessity to construct pseudo- potentials only with extreme care and caution.23 Acknowledgement is made to the National Science Foundation and to the Univer- sity of Florida for a grant of computer time.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry