We employ our previously published Ligand-Field Molecular Mechanics (LFMM) simulation setup for DUT-8(Ni). We perform three types of MD simulations: 1) CO2 in the rigid A conformer of DUT-8(Ni) using a fully flexible cell (NσT ensemble); 2) CO2 in the B conformer with a fully flexible cell (NσT ensemble); 3) CO2 in the B conformer with a fixed cell (NVT ensemble) in the op state. For details of the LFMM parametrization see ref , details of the MD simulations are given in the Supporting Information and adhere to the previous publications. Figure : Measured C NMR spectra of CO2 adsorbed in flexible (blue) and rigid (red) samples of DUT-8(Ni). Adapted with permission from Sin et al., Langmuir, 2019, 35 (8), 3162-3170. Copyright 2019 American Chemical Society. Line shape Simulation