A Temperature-dependent Structural Study of anti-ReO3-type Na3N: to Distort or not to Distort?

摘要

The rather open anti-ReO3-type crystal structure for sodium nitride is completely preserved in the temperature range between 20 K and its decomposition temperature at around 393 K according to temperature-dependent X-ray and neutron diffraction data collected on single crystals and microcrystalline powder of Na3N. Strong anisotropy of thermal displacement parameters even at low temperatures is attributed 10 purely dynamic effects. The tendency of ReO3-type and anti-ReO3-type compounds towards an octahedron-tilting distortion is compared theoretically by using cubic AlF3 and Li3N model compounds.