The current proposal seeks to establish the origin of t non-perovskite-like peak splitting observed in HRPD data for NaTaO3. It is our hypothesis that this is a result of the co-existence of two orthorhombic( Pnma & Cmcm ) phases at room temperature. This postulated to be consequence of a kinetic barrier to the re-arrangement of the tilts associated with the Pnma ¿ Cmcm transition. To test this hypothesis four samples of NaTaO3 prepared using different thermal annealing protocols will be studied, including some variable temperature measurements.