For the optimal direction for Coulombic interactions, we compute the Coulombic interaction of the adsorbate molecule pointing toward each of the atoms of the MOFs. The Boltzmann average of all the favorable orientations is calculated with a weighted Principal Component Analysis (wPCA). The Boltzmann average of all the unfavorable orientations is also calculated with a wPCA. The approximated optimal direction for Coulombic interactions is then the weighted average of the favorable direction and the projection of this favorable direction on the plane perpendicular to the unfavorable direction. The weight of the favorable and unfavorable directions is the fraction of the total Boltzmann energy of, respectively, the favorable and unfavorable interactions.