To better understand the selective adsorption behaviors of C 2 H 2 and C 2 H 6 over C 2 H 4 , the grand canonical Monte Carlo (GCMC) simulation was performed to gain insight into the nature of the binding sites for C 2 H 2 , C 2 H 4 , and C 2 H 6 in NKCOF-62. The simulated adsorption isotherms show a correct trend consistent with experiments that verify the reliability of the force field. As shown in Figure , C 2 H 2 , C 2 H 4 , and C 2 H 6 were all distributed at similar positions with the orthorhombic one-dimensional channel of NKCOF-62. In addition, these gas molecules all interacted with the aromatic hydrogen of TPA. The order of interaction distances was C 2 H 2 (2.71) < C 2 H 6 (2.99) < C 2 H 4 (3.28), and the corresponding adsorption energies were 38.81, 34.74, and 30.35 kJ/mol, respectively. These calculation results support the following trend in sorbentsorbate interactions for NKPOC-62: C 2 H 2 >C 2 H 6 >C 2 H 4 , which is fully consistent with the experimental findings.