Spin‐orbit ZORA and four‐component Dirac–Coulomb estimation of relativistic corrections to isotropic nuclear shieldings and chemical shifts of noble gas dimers |
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Authors: | Marzena Jankowska Teobald Kupka Leszek Stobiński Rasmus Faber Evanildo G. Lacerda Jr. Stephan P. A. Sauer |
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Affiliation: | 1. Faculty of Chemistry, University of Opole, Opole, Poland;2. Polish Academy of Sciences, Institute of Physical Chemistry, Warsaw, Poland;3. Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland;4. Department of Chemistry, University of Copenhagen, Copenhagen, Denmark |
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Abstract: | Hartree–Fock and density functional theory with the hybrid B3LYP and general gradient KT2 exchange‐correlation functionals were used for nonrelativistic and relativistic nuclear magnetic shielding calculations of helium, neon, argon, krypton, and xenon dimers and free atoms. Relativistic corrections were calculated with the scalar and spin‐orbit zeroth‐order regular approximation Hamiltonian in combination with the large Slater‐type basis set QZ4P as well as with the four‐component Dirac–Coulomb Hamiltonian using Dyall's acv4z basis sets. The relativistic corrections to the nuclear magnetic shieldings and chemical shifts are combined with nonrelativistic coupled cluster singles and doubles with noniterative triple excitations [CCSD(T)] calculations using the very large polarization‐consistent basis sets aug‐pcSseg‐4 for He, Ne and Ar, aug‐pcSseg‐3 for Kr, and the AQZP basis set for Xe. For the dimers also, zero‐point vibrational (ZPV) corrections are obtained at the CCSD(T) level with the same basis sets were added. Best estimates of the dimer chemical shifts are generated from these nuclear magnetic shieldings and the relative importance of electron correlation, ZPV, and relativistic corrections for the shieldings and chemical shifts is analyzed. © 2015 Wiley Periodicals, Inc. |
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Keywords: | 3He 21Ne 39Ar 83Kr 129Xe nuclear magnetic resonance Noble gas dimers chemical shifts molecular modeling zeroth‐order regular approximation four‐component Dirac– Coulomb density functional theory coupled cluster singles and doubles with noniterative triple excitations |
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