Dedicated to Professor Josef Breu on the Occasion of his 60 th Birthday lt-Ga 3 Ir is a low-temperature phase in the GaÀ Ir system, which is stable below 530 °C. The sample of lt-Ga 3 Ir was obtained after annealing at 400 °C for 96 hours. The crystal structure of lt-Ga 3 Ir was solved using 3D-ED electron diffraction data obtained by SA-EDT diffraction tomography, optimized by quantum-mechanical techniques and refined from the X-ray powder diffraction data: structure type Fe 3 C, space group Pnma, a = 6.9073(4) Å, b = 7.7275(4) Å and c = 4.8536(2) Å, Z = 4, Pearson symbol oP16. The striking feature of the chemical bonding is the absence of the two-atomic GaÀ Ga bonds. The two-atomic Ga1À Ir and Ga2À Ir, as well as the three atomic Ga1À Ga2À Ir bonds, form the bonding pattern.