The integration of the electron density and its derivatives has been obtained with the grid of the density function. The accuracy of the grid was controlled by the integration of the resulting radial distribution of the density to the proper number of electrons. The grid for atoms/ions in the 1st and 2nd periods was 0.05ao with the integration radius 15 ao. For the 3rd and 4th period the grid was 0.02 ao within the radius 20 ao.