Correlation-consistent valence basis sets were developed for the third-row main block Ž . elements K, Ca, GaᎏKr for use with relativistic effective core potentials. These basis sets are somewhat larger than double-zeta in size, with polarization functions, and are balanced for use in both Hartree᎐Fo
Atomic orbital basis sets for use with effective core potentials
✍ Scribed by J.-P. Blaudeau; S. R. Brozell; S. Matsika; Z. Zhang; R. M. Pitzer
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 372 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0020-7608
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✦ Synopsis
Basis sets developed for use with effective core potentials describe pseudo-orbitals rather than orbitals. The primitive Gaussian functions and the contraction coefficients in the basis set must therefore both describe the valence region effectively and allow the pseudo-orbital to be small in the core region. The latter is particularly difficult using 1s primitive functions, which have their maxima at the nucleus. Several methods of choosing contraction coefficients are tried, and it is found that natural orbitals give the best results. The number and optimization of primitive functions are done following Dunning's correlation-consistent procedure. Optimization of orbital exponents for larger atoms frequently results in coalescence of adjacent exponents; use of orbitals with higher principal quantum number is one alternative. Actinide atoms or ions provide the most difficult cases in that basis sets must be optimized for valence shells of different radial size simultaneously considering correlation energy and spin-orbit energy.
📜 SIMILAR VOLUMES
A new approach for developing of basis sets to be used along with effective core potential is systematically studied. The behavior of the Ž . LCAO coefficients versus the ln ␣ of the respective primitives can provide simple guidelines to establish the range over which the basis set should be develop
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The nuclear shielding of 99 Ru in several complexes has been investigated computationally by DFT methods with effective core potential and all-electron basis sets. Shieldings calculated with ECP bases correlate very satisfactorily with available experimental data, although they are ca. one order of
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