A gas consisting of N noninteracting diatomic molecules is confined within a volume V. The kinetic energy of each molecule contains terms associated with both translation and rotation, so that the corresponding (single particle) Hamiltonian is
$$H_1(r, \theta, \phi, p, p_\theta, p_\phi) = \frac{p \cdot p}{2m} + \frac{p_\theta^2}{2I} + \frac{p_\phi^2}{2I \sin^2 \theta},$$
where $m$ is the mass of the molecule and $I$ its moment of inertia.
(a) Calculate the partition function $Z(T, V, N)$ in the canonical ensemble and the free energy of the system, $F(T, V, N)$.
(b) Calculate the coefficients $c_V = C_V/N$ and $c_p = C_p/N$, and the adiabatic coefficient $\gamma$ for the diatomic gas. Compare the results with the corresponding quantities for the monoatomic ideal gas.