Linear augmented-plane-wave frozen-phonon calculation, shell-model lattice dynamics, and specific-heat measurement of SnO

An ab initio linear augmented-plane-wave (LAPW) calculation of the zone-center phonon frequencies of SnO has been performed. $E_g$ symmetry has been ascribed to the mode observed at $113\hspace{0.5em}{\mathrm{cm}}^{-1}$ in Raman measurements, discarding a previous $B_{1g}$ assignment. The other phonon modes measured by Raman spectroscopy are also well reproduced. A shell model has also been developed that gives good agreement of the zone-center frequencies compared to the measured data and the LAPW results. Specific-heat measurements have been performed between 5 and 110 K. Computation of the specific heat and the Mössbauer recoilless fraction with the improved shell model shows a good agreement with the experimental data as a function of temperature.