Recovery of harmonic-like behavior of the polar mode in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="normal">BaTiO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math> at high pressures

The local structure of high-pressure ${\mathrm{BaTiO}}_{3}$ has been interrogated by neutron total scattering methods up to pressures 4.18 GPa at ambient temperature. Competitive refinements cubic, tetragonal, and rhombohedral distortion modes against pair distribution functions indicate contrasting behavior temperature- pressure-induced cubic ${\mathrm{BaTiO}}_{3}$. Suppression the mode amplitude, isotropy order-parameter direction, loss sensitivity correlated Ti displacements high pressure all suggest a that is more consistent with harmonic approximation rather than an order-disorder model which better describes high-temperature in vicinity tetragonal phase transition.