The influence of representation the wave function on the results of a computer simulation of filling fullerene molecules by hydrogen was considered. The calculations were carried out with the density functional method using the basis functions of the form 6-31G, 6-31G**, SDD and LanL.2DZ in the Gaussian09 software package. It is shown that the number of hydrogen molecules that can freely fit into the fullerene cavity increases when using bases with pseudopotential. The dependence of calculation results from the type of the exchange-correlation potential in density functional theory is more significant than the dependence on the means of representing the wave function. Refs 14. Fig. 1. Tables 2.