In an x-ray diffraction experiment on a crystal that has a cubic lattice, the smallest Bragg angle at which you see a peak in the intensity of diffraction pattern is \(15.00^{\circ}\). If the \(x\)-ray are produced from a copper source \((0.154 \mathrm{~nm})\), what is the atomic spacing in the crystal? Assume that only first-order interference fringes are visible in the diffraction pattern of this crystal.