Solid State

As X is present at the corners of the cube and also at the faces of the cube, so the contribution of X will be 8 (corners) × $\frac{1}{8}$ × (contribution of each corner atom) + 6 (faces) × $\frac{1}{2}$ (contribution of each face) = 4 As M is present at the body centre and at each diagonal, so its contribution will be 4 (diagonals) × $\frac{1}{4}$ (contribution of each diagonal) + 1 (body centre) = 2 So, the unit cell formula becomes $\mathrm{M}_2\mathrm{X}_4$ and the empirical formula will be $\mathrm{M}\mathrm{X}_2$.