From reaction of excess lithium with tin, we isolate well-crystallized Li 5 Sn and solve the crystal structure from single-crystal X-ray diffraction data. The orthorhombic structure (space group Cmcm ) features the same coordination polyhedra around tin and lithium as previously predicted by electronic structure calculations for this composition, however differently arranged. An extensive ab initio analysis, including thermodynamic integration using Langevin dynamics in combination with a machine-learning potential (moment tensor potential), is conducted to understand the thermodynamic stability of this Cmcm Li 5 Sn structure observed in our experiments. Among the 108 Li 5 Sn structures systematically derived using the structure enumeration algorithm, including the experimental Cmcm structure and those obtained in previous ab initio studies, another new structure with the space group Immm is found to be energetically most stable at 0 K. This computationally discovered Immm structure is also found to be thermodynamically more stable than the Cmcm structure at finite temperatures, indicating that the Cmcm Li 5 Sn structure observed in our experiments is favored likely due to kinetic reasons rather than thermodynamics.

Two ternary nitride perovskites Co3InN and Ni3InN have been synthesized electrochemically at 723 K in a molten salt LiCl/KCl:Li3N. The working electrode, which was either a pre‐molten alloy of Co/In or Ni/In, was anodically polarized at 2.6 V during synthesis. Lattice parameters refined by the Rietveld method are a = 385.180(8) pm for Co3InN and a = 385.99(1) pm for Ni3InN. EDX measurements confirm the atomic ratios of 3:1 of the metallic elements. Chemical analyses on nitrogen content result in compositions of Co3InN1.13 and Ni3InN0.95, respectively. Furthermore, particle size of Co3InN is 1–3 µm and of Ni3InN 5–20 µm. Co3InN shows spin‐glass behavior with a freezing temperature of about 11 K at 100 Oe.

Two iron nitrides γ-FeN 0.13 and ε-Fe 3 N 1.51 were synthesized electrochemically in a molten salt system KCl-LiCl at 450°C. For the electrochemical formation of γ-FeN 0.13 , which crystallizes in Fm3m with a = 367.46(7) pm, either Li 3 N or KNO 3 can be added to the salt mixture as nitrogen source. An addition of Li 3 N corresponds to anodic polarization (anodic electrolysis) of the working electrode and KNO 3 to cathodic polarization (cathodic electrolysis). The chosen applied voltages were 0.8 V and 1.4 V, respectively. Electrochemical synthesis employ- [a]

The three nitrides ε-TaN, δ-NbN and γ′-Mo2N have been synthesized electrochemically from the elements at 450°C in a molten salt mixture LiCl/KCl:Li3N. For all compounds the working electrode consisting of a tantalum, niobium or molybdenum foil was anodically polarized and the system was fed with dry nitrogen. The applied constant voltage was 2.5 V (for ε-TaN), 2.2 V (for δ-NbN), and 2.8 V (for γ′-Mo2N). Chemical analysis on N and O resulted in compositions of TaN0.81(1)O0.13(2), NbN1.17(2)O0.28(1) and MoN0.88(1)O0.11(1), respectively. Lattice parameters of ε-TaN refined by the Rietveld method are a =  519.537(4) and c = 291.021(3) pm. The other two nitrides crystallize in the cubic system (rocksalt type) with a = 436.98(2) pm for δ-NbN and with a = 417.25(2) pm for γ′-Mo2N.

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