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Abstract

The ternary solid solution Na2Ga7−xInx (x≤0.25) was synthesized by annealing the elements at 300 °C in sealed Ta ampoules. Differential thermal analysis (DTA) indicated incongruent phase formation. The peritectic temperature ranges from 501(2) °C (x=0) to 474(2) °C (x=0.25). In addition, the unit cell parameters increase significantly with In content. At its maximum of x=0.25, the unit cell volume increases by 1 compared to Na2Ga7. The In positions are deduced from single-crystal X-ray diffraction data obtained for the composition Na2Ga6.95In0.05 (space group Pnma; Z=8; a=14.876(3) Å, b=8.688(2) Å, c=11.605(4) Å). In the crystal structure of Na2Ga7, which consists of Ga12 icosahedra and 4-bonded Ga atoms, the In atoms solely substitute the latter. The Na atoms are located in the channels and cavities of the framework. The phase is electron-precise and can be considered a Zintl-Wade compound with the formula unit [Na+]16[(12b)Ga122−]4[(4b)Ga−]7.6[(4b)In−]0.4. © 2024 The Authors. European Journal of Inorganic Chemistry published by Wiley-VCH GmbH.