Calculations for the photoionization cross-sections of atomic and molecular levels for the Al Kα and Mg Kα lines depending on the wave function of the final and the initial states are analysed. The ns, np, and nd photoionization cross-sections of atomic shells for Z ⩽ 36 and the HF, NH 3, H 2O, CH 4, CH 3F, CH 2F 2, CHF 3, CF 4, N 2, CO, and C 2H 4 molecular levels for the YMξ line and the photoionization cross-sections of atoms for Z ⩽ 36 and the CH 4, N 2, and H 2O molecular levels for the ZrMξ line are calculated. Photoionization cross-section calculations using the Hartree—Fock—Slater potential are better agreement with experiment than those using orthogonalized plane waves for photoelectron wave functions.