| Abstract: | The structure of a new magnesium nitridoboride, MgNB9, has been refined from single‐crystal X‐ray data. The Mg and N atoms lie on sites with crystallographic 3m symmetry. The structure consists of two layers alternating along the c axis. The NB6 layer, with B12 icosahedra, has the C2B13 structure type. Within this layer, boron icosahedra are bonded to N atoms, each coordinating to three boron polyhedra. Another MgB3 layer, with B6 octahedra, does not belong to any known structure type. The boron icosahedra and octahedra are connected to each other, thus forming a three‐dimensional boron framework. |
