The spectra of magneto-optics and of absorption coefficient of UO₂ caused by the intra-atomic 5f-6d dipole transitions are calculated assuming the electro static, the spin-orbit interactions and the cubic crystalline field, and the results fitted to the experiments are obtained. Then, the atomic Slater-Condon parameters and the spin-orbit coupling constants of U⁴⁺ interpolated from those of Th²⁺ combined with the atomic structure calculation are used, and the exchange integrals G_k (k=1, 3, 5) and the crystalline field parameter for 6d electron in 5f6d configuration are taken as abjustable ones. It is shown that the best values of them are A₄<r⁴>=1600cm^-1 and 1.3G_k, where G_k are the values evaluated from the atomic structure calculation. It is clarified that the crystalline field plays an important role since the energy separation between two main peaks is nearly equal to splitting due to it.