Diatomic chain. Consider the normal modes of a linear chain in which the force constants between nearest-neighbor atoms are alternately C and 10C. Let the masses be equal, and let the nearest-neighbor separation be a/2. Find w(K) at K = 0 and K = π/a. Sketch in the dispersion relation by eye. This problem simu- lates a crystal of diatomic molecules such as H₂.

Diatomic chain. Consider the normal modes of a linear chain in which the force constants between nearest-neighbor atoms are alternately C and 10C. Let the masses be equal, and let the nearest-neighbor separation be a/2. Find w(K) at K = 0 and K = π/a. Sketch in the dispersion relation by eye. This problem simu- lates a crystal of diatomic molecules such as H₂.