Vibrational entropy ($S_{\mathrm{vib},\mathrm{m}}/R=x/(e^x-1)-\ln (1-e^{-x})$)

The harmonic-oscillator entropy contribution for one vibrational coordinate, with $x={\theta }_{\mathrm{vib}}/T$. Contributions from independent normal modes add, with one term for each component of a degenerate mode. A temperature-independent zero-point energy does not change this entropy.