▎ 摘　　要

We performed benchmark calculations to study the complexes of pyridine with beryllium, magnesium, and calcium. In all cases, the sigma structures, in which the alkaline-earth element interacts with nitrogen, were found to be more stable than the ones featuring interactions with the pi cloud. At the CCSD(T)/CBS level of theory, the dissociation energies (D-e) are 6.5, 3.7 and 7.2 kcal/mol, for beryllium, magnesium, and calcium, respectively.ew Our estimation of the D-0 of the calcium-pyridine complex is in excellent agreement with the experimental value. For comparative purposes, we studied the performance of the M06-2X, PBE-D3BJ, vdW-DF, and B2PLYP-D2BJ density functionals. All of the DFT methods employed significantly overestimated the dissociation energies. Finally, in light of the results obtained, pyridinic nitrogen is the doping configuration to be chosen in nitrogen-doped graphene to improve the adsorption of alkaline-earth elements on this material.