Correlation consistent, Douglas–Kroll–Hess relativistic basis sets for the 5p and 6p elements
Correlation consistent, Douglas–Kroll–Hess relativistic basis sets for the 5p and 6p elements
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DOI：
10.1007/s00214-013-1434-9
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发表时间：
2014-02
影响因子：
1.7
通讯作者：
David H. Bross;K. Peterson
中科院分区：
文献类型：
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作者：
David H. Bross;K. Peterson
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New sets of all-electron correlation consistent triple- and quadruple-zeta basis sets have been developed for the 5pand 6pelements (In–Xe, Tl–Rn). For the 5pelements, the spin-free Douglas–Kroll–Hess (DKH) Hamiltonian truncated at second order was used, while for the 6prow, DKH3 was employed. The resulting cc-pVmZDK sets (m = T,Q) are designed to correlate the valencensandnpelectrons, but both core–valence sets (cc-pwCVmZ-DK) for (n - 1)spdcorrelation and diffuseaugmented sets (aug-cc-pVmZ-DK) for weak interactions have also been included. Benchmark DKH CCSD(T) calculations were carried out on the atoms for their first ionization potentials and electron affinities. Coupled cluster calculations of the near-equilibrium potential energy functions of 18 selected diatomic molecules were also carried out to determine their spectroscopic and thermodynamic properties. These results are extensively compared to those obtained using the analogous aug-ccp( wC)VmZ-PP basis sets with their associated small-core pseudopotentials. For the quadruple-zeta quality basis sets, the mean unsigned differences were found to be just 1.4 mÅ for re, 0.7 cm-1 for xe, and 0.2 kcal/mol forDe with corresponding maximum differences of 4.8 mÅ, 4.3 cm-1, and 0.7 kcal/mol, respectively. Using all-electron DKH calculations with the present basis sets as corrections to the pseudopotential approximation appears to be most accurate when (n - 1)d correlation is considered in both cases using aug-cc-pwCVQZ quality basis sets. The new DK basis sets exhibit similar basis set convergence toward the complete basis set (CBS) limit as the PP-based sets and hence should find utility in all-electron [T,Q] basis set extrapolations.