Synthesis and crystal structure of the pyrovanadate Na ₂ ZnV ₂ O ₇

Abstract

The compound Na 2 ZnV 2 O 7 with an åkermanite-type structure has been synthesized. It has a tetragonal unit cell, a =8.2711(4), c =5.1132(2) Å, and crystallizes with P -42 1 m symmetry, Z =2. Its crystal structure has been refined from a combination of X-ray and neutron powder diffraction data. The structure contains layers of corner-sharing VO 4 and ZnO 4 tetrahedra, the former in pairs forming pyrovanadate V 2 O 7 units. The sodium atoms are positioned between the layers, with a distorted antiprismatic coordination of oxygen atoms.