  An ab-initio Linear Augmented Plane-Wave (LAPW) calculation of the
zone-centered phonon frequencies of SnO has been performed. E$_g$ symmetry has
been ascribed to the mode observed at 113 cm$^{-1}$ in Raman measurements,
discarding a previous B$_{1g}$ assignement. The other phonon modes measured by
Raman spectroscopy are also well reproduced. A new shell-model has also been
developed, that gives good agreement of the zone-centered frequencies compared
to the measured data and the LAPW results. Specific heat measurements have been
performed between 5 K and 110 K. Computation of the specific heat and the
M\"{o}ssbauer recoilless fraction with the improved shell-model shows a good
agreement with the experimental data as a function of temperature.
