 Electronic heat capacity coefficient

For a Fermi liquid, $C_{\mathrm{el}}=\gamma T+o(T)$ at low temperature. In a simple quasiparticle description, $\gamma =({\pi }^2/3)k_B^{2}g(E_F)$, where the density of states includes both spin states and uses the same per-volume or per-mole normalization as $\gamma$. A fit $C/T=\gamma +\beta T^2$ separates this contribution from a Debye lattice term over an appropriate low-temperature range. Magnetic or other low-energy excitations can require extra fit terms.