where the elements T (ℓℓ ′ ) are the interaction tensors between the multipole moments, with the correct long-range dependency and a parameterized short-range damping in the overlapping regime. For the GFN1-xTB method, the expansion is truncated already for the monopole moments, while in GFN2-xTB, contributions up to second order in the energy (dipole-dipole and charge-quadruple) are included. Note that the short-range damping of this electrostatic energy implicitly accounts for correlation effects.