This initial implementation speeds up the calculation of adsorption enthalpy in nanoporous materials by sampling interaction energies only near the surface. It is illustrated in Fig- 2. For this purpose, a loop over all unique atoms (as defined by crystalline symmetry) is performed. And for each atom, a sphere around its position is sampled using a uniform distribution around it, these points will be called sampling points and we can change the number of sampling points. The default radius chosen for the sampling spheres is the distance 𝑟 min = 2 1/6 𝜎 𝑖𝑗 to the minimum of the LJ potential between atoms of type 𝑖 (belonging to the framework) and 𝑗 (the guest), corresponding to the strongest possible pair interaction (although the neighboring atoms will of course have an influence). After calculating the interaction energy at each of the sampled points, a Boltzmann average of these energies corresponds to a biased adsorption enthalpy, as described by the equation 1.