Grand canonical ensemble Monte Carlo computer simulation is employed to obtain the adsorption isotherms of nitrogen, at 77.5 K, on a columnar carbonaceous material. The solid constructed is based on the Bernal model. At moderate equilibrium pressures, the intercolumnar space is filled with nitrogen in a liquidlike state. The distributions of molecules with respect to gas-solid and gas-gas interaction energies are analyzed. The role played by quadrupolar interactions is discussed. The supersite theory of adsorption applied to this system gives a good description of the simulation results.