Signature at 400 cm -1 . The intense peak centered at 396 cm -1 in the experiment undergoes a red-shift to 383 cm -1 and a small decrease in intensity upon CO adsorption, while no significant change is found upon CO2 adsorption. In this region, the computed S(ω) for the bare MOF predicts an intense peak at ca. 400 cm -1 , named D, and a smaller peak at ca. 411 cm -1 . Upon CO adsorption, peak D shifts to lower energy and splits into peak D ′ at 385 cm -1 and D ′′ at 396 cm -1 (see Figure ). For CO2, the computed S(ω) exhibits a single peak, named D ′′′ , located almost at the same position as D (ca. 399 cm -1 ). For both molecules, we see a small peak centered at around 413 cm -1 which moves negligibly with respect to the bare material.