  We consider a multiatomic system where the nuclei are assumed to be point
charges at fixed positions. Particles interact via Coulomb potential and
electrons have pseudo-relativistic kinetic energy. We prove the van der
Waals-London law, which states that the interaction energy between neutral
atoms decays as the sixth power of the distance $|D|$ between the atoms. We
rigorously compute all the terms in the binding energy up to the order
$|D|^{-9}$ with error term of order $\mathcal{O}(|D|^{-10})$ . As intermediate
steps we prove exponential decay of eigenfunctions of multiparticle
Schr\"odinger operators with permutation symmetry imposed by the Pauli
principle and new estimates of the localization error.
