A cubic solid is made up of two elements X and Y. Atoms of X are present on every alternate corner and one at the center of cube. Y is at \( 1/3 \) rd of the total faces. The empirical formula of the compound is:
$\text{XY}_{2.5}$
$\text{X}_{2.5}\text{Y}$
$\text{X}_{1.5}\text{Y}_2$
$\text{X}_2\text{Y}_{1.5}$