The crystal structure of ammonium metavanadate

Abstract

The paper deals with the structure analysis of ammonium metavanadate NH4VO3from photographs obtained with a Weissenberg goniometer using CnKαand MoKαradiation. The dimensions of the orthorhombic unit cell determined from these photographs of the rotating crystal are a=4.92, b=11.82, c==5.85 Å. A satisfactory space group is Pbcm (D2h11), with four molecules in the unit cell. The positions of the atoms in the unit cell were determined by means of the Patterson functions P(v, w), P(u, v) and from the projection of the electron density on the (001)plane. An analogy was found with the structure of the metasilicates from the pyroxen group. The oxygen atoms are coordinated tetrahedrally around the vanadium atoms. The tetrahedra VO4form infinite chains in the direction of the [001]axis. The VO4chains are mutually bonded by means of electrostatic bonds of the NH4ions. The splitting of the chains in an aqueous solution is connected with the dissociating and catalytic properties of the ammonium metavanadate. © 1954 Czechoslovak Academy of Sciences.