0 "fig:"){width="0\columnwidth"} ![\[fig:detailscan\] The dispersion of the TA0 phonons softens and hardens at $q = (\overline{0.000}\ 0.000\ 0)$ (top) and $q = (\overline{0.0}\ 0.0\ 0)$ (bottom), respectively, when approaching the cubic-tetragonal phase transition near $T_{OO} = 00$ K from high temperatures. For $q = (\overline{0.0}\ 0.0\ 0)$ (middle) there is no change in phonon energies in the $T > T_{OO}$ region. Please note that at MIRA we measured using neutron energy gain ($-E$) for reasons of analyser efficiency and angular constraints at the instrument. The physics of the system is unaffected by this choice. ](q0 "fig:"){width="0\columnwidth"} ![\[fig:detailscan\] The dispersion of the TA0 phonons softens and hardens at $q = (\overline{0.000}\ 0.000\ 0)$ (top) and $q = (\overline{0.0}\ 0.0\ 0)$ (bottom), respectively, when approaching the cubic-tetragonal phase transition near $T_{OO} = 00$ K from high temperatures. For $q = (\overline{0.0}\ 0.0\ 0)$ (middle) there is no change in phonon energies in the $T > T_{OO}$ region. Please note that at MIRA we measured using neutron energy gain ($-E$) for reasons of analyser efficiency and angular constraints at the instrument. The physics of the system is unaffected by this choice. ](