A central quantity of interest for molecular spin dynamics is the phonon DoS. The DoS is often obtained evaluating phonon frequencies on a chosen q-point grid and applying Gaussian or Lorentzian smoothing functions with an arbitrary linewidth (e.g. Figure ). Here, because we have calculated the mode-dependent linewidths from first principles, we can directly construct the DoS without an artificial smoothing function (Figure ). The resulting low-energy DoS is sharply featured when using a small 2×2×2 q-point grid due to the coarse sampling of the Brillouin zone. The low-energy DoS as 𝜔 → 0, determined solely by the three acoustic modes, is expected to be a quadratic function of frequency, and this behaviour in the low-energy DoS is better approximated using a larger 5×5×5 q-point grid to sample the dispersion of these modes more accurately; although we note that this grid still does not fully capture the lowenergy dispersion (cf. Figure ). We also note that using a small grid would be more problematic at lower temperatures given the drastic narrowing of the linewidths (Figure ).