The Ba2.64Ta11.25O30.81was prepared by conventional solid-state reaction technique as a single phase. It was found that the compound crystallizes in the tetragonal system, space group P4/mbm (No. 127) and unit-cell parameters are a = 12.508 59(8) Å, c = 3.912 81(2) Å, V = 612.218(7) Å3, and Z = 1. The crystal structure of the Ba2.64Ta11.25O30.81 phase is found to be closely related to the tetragonal tungsten bronze structure type, comprising interstitial (TaO)+ inclusions. Reference data were derived from the Rietveld analysis and reported here.
