For this work, in order to reduce the influence of the chemical environment, for all calculated effective vdW radii we estimate the vdW radius for the free hydrogen atom by re-scaling them with the ratio between the free atomic length L, and the effective Hirshfeld lengths, employing new proposed scaling laws. More details are provided in the Supporting Information. This procedure is then similar to the inverse of Eq. 1, and it is fundamentally different from alternative corrections from charged to neutral hydrogen systems. Let us now examine the definition of equilibrium vdW radii for non-covalently interacting hydrogen systems. One of the earliest definitions of a vdW radius was established by Bondi in terms of the distance at which the Pauli repulsion balances the attraction forces between the two atoms. Nevertheless, the above definition must be adopted carefully since there is no unique approach to quantify non-covalent attractive and repulsive forces between two atoms in a molecule. Among the many existing quantum chemistry approaches, symmetry-adapted perturbation theory (SAPT) allows computing and decomposing the total interaction energy between two noncovalently bonded subsystems into physically intuitive terms such as electrostatics, induction, exchange repulsion, and dispersion E int = E elst +E exch +E ind +E disp , while keeping an accuracy of interaction energies close to the CCSD(T) "gold standard". For the above reason, we employed the SAPT methodology to explore the aforementioned balance of attractive and repulsive forces in the interaction of vdW systems. The Supporting Information provides a more detailed description of the calculations. The SAPT forces were computed by numerical differentiation of each energy component with respect to the internuclear separation F comp = -∂Ecomp ∂R . All SAPT and CCSD(T) calculations presented in this work were obtained with the PSI4 code. To provide the first estimate of hydrogen vdW radius, we examine a simple system containing neutral hydrogen atoms -the hydrogen molecule in its triplet state. This system exhibits a very small binding energy of 4.3 cm -1 at an internuclear separation of 7.85 Bohr. Here, the SAPT decomposition indicates that at the equilibrium distance of the triplet H 2 , the main contribution to the attractive forces comes from the dispersion terms by 83%, while electrostatics is 11%, induction is 5%, and the repulsive force is only due to exchange, suggesting that vdW interactions play a substantial role in the binding mechanism of triplet H 2 . Therefore, we pencil in 3.92 Bohr as a first estimation of the effective hydrogen vdW radius [using half of the equilibrium distance in triplet H 2 at the CCSD(T)/CBS level of theory], same value is obtained for the corrected free vdW radii in this case due to the small variation in size at such large distances.