Atomic C _6 dispersion coefficients: A four-component relativistic Kohn-Sham study

摘要

We present C _6 homo- and heteroatomic dispersion coefficients for all closed-shell atoms of the periodic table based on dipole-dipole polarizabilities at imaginary frequencies calculated using our recent extension of the complex polarization propagator approach to the four-component relativistic Kohn-Sham approach. Lack of proper reference data bars definite conclusions as to which density functional shows the overall best performance, and we therefore call for state-of-the-art wave function-based correlated calculations of dispersion coefficients. Scalar relativistic effects are significant already for elements as light as zinc, whereas spin-orbit effects must be taken into account only for very heavy elements.