Synthesis and Approximated Crystal and Electronic Structure of a Proposed New Tantalum Oxide Nitride Ta3O6N

In the quasibinary system Ta₂O₅/Ta₃N₅ we prepared a new oxide nitride phase, Ta₃O₆N, by the reaction of 1T–TaS₂ with water‐saturated ammonia gas. The determination of the unit cell metric and the crystal structure indicated that Ta₃O₆N is structurally related to the TiNb₂O₇‐type. Quantum‐chemical calculations on DFT level were used to rank the relative stabilities of possible N/O distributions and to provide a plausible structural model of the ground state with a minimum in the total energy. In agreement with Paulings 2nd rule, nitrogen ions prefer sites with high coordination numbers.