The crystal structure of potassium tungstate, K₂WO₄

Abstract

K2WO4 crystallizes in space group C2/m with the axes a 12.39, b 6.105, c 7.560 A., and b 115.96 Deg. The 4 formula units per unit cell form layers parallel to (001), in which each WO4 tetrahedron is surrounded by an almost regular hexagon of K ions. The W-O bond length is 1.79 A., and the K-O and O-O distances are in general agreement with the accepted values. This structure type occurs also in other A2BX4 compds., among which are K2MoO4, Rb2WO4, Rb2MoO4, (NH4)2MoO4, (NH4)2SeO4, and (NH4)2CrO4.