X-ray powder diffraction pattern was used to determine the length of the unit cell, “a”, the lattice structure type, and the number of atoms per unit cell of Ni(II) crystal. The “a” value was determined to be 23.66 ± 0.005 Å, particle size of 34.87 nm, volume 13.24 Å and Strain value ε = 9.8 x 10-3. The cell search on PXRD patterns shows that the nickel (II) complex crystallizes in cubic structure with space group Fd3m and Z = 8. The experimental value of “a” was determined to be 23.66 ± 0.005 Å. It was deduced that the structure being face-centered cubic has the same number of electrons and therefore make one eighth of the actual unit cell. Taking this into consideration, each unit cell contains 4 atoms. The morphology and elemental composition of the Ni(II) was determined using Scanning Electron Microscopy coupled with Energy-Dispersive X-ray analysis. It was concluded that the unit cells and space groups were determined directly from the powder diffraction data.Key Words: Powder X-ray Diffraction, unit cell, Crystal Structur