Citation: Chahboun, H; Groult, D; Hervieu, M; Raveau, B (1986). $-beta Nb P O5 and $-beta Ta P O5: Bronzoids, second members of the monophosphate tungsten bronze series (P O2)4 (W O3)2M. Journal of Solid State Chemistry, 65, pp. 331-342.
Formula: O5 P Ta
Chemical name:Tantalum phosphorus pentoxide - $-beta