Crystal structure of KNaCuP2O7, a new member of the diphosphate family

Abstract

Potassium sodium copper(II) diphosphate(V), KNaCuP2O7, was synthesized by solid-state reactions. It crystallizes in the α-Na2CuP2O7 structure type in space group P21/n. In the crystal, CuO5 square-pyramids are linked to nearly eclipsed P2O7 groups by sharing corners to build up corrugated layers with composition [CuP2O7]2− that extend parallel to (010). The K+ and Na+ cations reside in the interlayer space and are connected to nine and seven O atoms, respectively. The structural model was validated by bond-valence-sum (BVS) and charge-distribution (CHARDI) analysis.