Quantum Drude Oscillator Model: Optimized parametrization for all elements in the Periodic table.

The quantum Drude oscillator (QDO) provides a minimal and robust model of electrical response properties of matter by replacing the electron cloud oscillations on each atom with an effective quantum harmonic oscillator. Three parameters characterize each QDO (mass, frequency, and charge), usually adjusted to reproduce three atomic response properties. Here, we present a more general parametrization of the QDO, valid for all the elements in the periodic table that uses only the static polarizability α₁ and dipole-dipole C₆ dispersion coefficient. As an additional constraint, we impose the relation between the polarizability and vdW radius, as derived in [Fedorov et al., PRL 121, 183401 (2018); Vaccarelli et al., Phys. Rev. Research 3, 033181 (2021)]. By using only α₁ and C₆ as initial observables, the new parametrized QDO model can accurately describe the response properties of all atoms and different small molecules, with straightforward access to higher-order multipole polarizabilities and vdW radii. In addition to providing accurate and efficient representation of response properties of atoms and molecules, our optimized QDO model brings novel insights into scaling behavior and an upper limit on atomic polarizability