Novel corrugated In9 anionic layer in Li2Y5In9: square pyramidal In5 clusters interconnected by unusual butterfly In4 clusters.

The new ternary polar intermetallic phase, Li2Y5In9, was obtained by high-temperature solid-state reactions of the corresponding elements inwelded Ta tubes. Its crystal structure was established by a single-crystal X-ray diffraction study. Li2Y5In9 crystallizes in the tetragonal space group P4/nmm (No.