To identify the set of { ωi } we start by introducing a corresponding set of bare isotropic and static atomic polarizabilities {α i (0)} which, in the original Tkatchenko-Scheffler scheme , is obtained by partitioning of the total electron density via the Hirshfeld decomposition or, alternatively, via an iterative Hirshfeld scheme. The static polarizabilities are turned into frequency-dependent ones by employing the [0/2] Pade approximants' form in Eq. (3). ω 0 j is the free-atom resonant frequency which is defined in terms of the free-atom's first dispersion coefficient and static polarizability, C 0 6, j and α 0 j (0) respectively. We note in passing that both quantities can be obtained from accurate ab initio calculations.