The compound is prepared by the addition of ammonium salts to solutions of vanadate ions, generated by dissolution of VO in basic aqueous solutions, such as hot sodium carbonate.  The compound precipitates as a colourless solid. This precipitation step can be slow.
The compound adopts a polymeric structure consisting of chains of [VO], formed as corner-sharing VO tetrahedra.  These chains are  interconnected via hydrogen bonds with ammonium ions.