Internal energy
The internal energy is given by
- Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle U=-T^2 \left. \frac{\partial (A/T)}{\partial T} \right\vert_{N,V} = k_B T^{2} \left. \frac{\partial \log Z(T)}{\partial T} \right\vert_{N,V}}
where is the Helmholtz energy function and Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle Z} is the partition function.
