Fig. 2. Annealed structures of the BDC-based Mg-MOF-74–25H₂ system (on the left) and DHF-based Mg-MOF-74–12H₂ systems (on the right) starting from three different initial configurations sampling within the 300 K NVT ensemble. Red, brown, cyan and white spheres represent oxygen, magnesium, carbon and hydrogen atoms of the frameworks. Hydrogen atoms of the molecules adsorbed at P₁, P₂, P₃, P₄ and P₅ sites of the BDC-based framework are represented by blue, yellow, green, pink and white spheres respectively. Hydrogen atoms of the molecules adsorbed at P₁, P₂ and P₃ sites of the DHF-based framework are represented by blue, pink and white spheres respectively.