Hi, Just starting a solids course got a bit thrown by this, haven't done much thermodynamics which seems to be relevant here. Q: The interatomic binding of a materail is such that it can be considered classicallly with the bonds being treated as if they are harmonic springs with three different spring constants in each side of the atom: k1, k2 and k3. Not sure how an atom has a side, but anyway does this question means just to consider with three bonds to other atoms i.e. Ammonia? Calculate the energy, E, stored in each of these bonds I'm thinking this is just E1 = 0.5k1X^2, E2 = 0.5k2X^2, and E3 =0.5k3X^2 Then it asks to show that the heat capacity is independant of both the temperature and spring constants. I'm thinking it's connected to the average energy which is KBT for a classical harmonic oscillator. C = DU/DT at constant V, but I'm not really sure how to go between the energy equations, average energy and C.