An accurate set of benchmark rotational tensors and magnetizabilities are calculated using coupled-cluster singles-doubles (CCSD) theory and coupled-cluster single-doubles-perturbative-triples [CCSD(T)] theory, in a variety of basis sets consisting of (rotational) London atomic orbitals. The accuracy of the results obtained is established for the rotational tensors by careful comparison with experimental data, taking into account zero-point vibrational corrections. After an analysis of the basis sets employed, extrapolation techniques are used to provide estimates of the basis-set-limit quantities, thereby establishing an accurate benchmark data set. The utility of the data set is demonstrated by examining a wide variety of density functionals for the calculation of these properties. None of the density-functional methods are competitive with the CCSD or CCSD(T) methods. The need for a careful consideration of vibrational effects is clearly illustrated. Finally, the pure coupled-cluster results are compared with the results of density-functional calculations constrained to give the same electronic density. The importance of current dependence in exchange–correlation functionals is discussed in light of this comparison.
Benchmarking density-functional-theory calculations of rotational tensors and magnetizabilities using accurate coupled-cluster calculations
Ola B. Lutnæs, Andrew M. Teale, Trygve Helgaker, David J. Tozer, Kenneth Ruud, Jürgen Gauss; Benchmarking density-functional-theory calculations of rotational tensors and magnetizabilities using accurate coupled-cluster calculations. J. Chem. Phys. 14 October 2009; 131 (14): 144104. https://doi.org/10.1063/1.3242081
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