Materials Data on KAl(H2N)4 by Materials Project
KAl(NH2)4 crystallizes in the orthorhombic C222_1 space group. The structure is one-dimensional and consists of twelve hydrogen molecules and two KAl(N2H)2 ribbons oriented in the (0, 0, 1) direction. In each KAl(N2H)2 ribbon, K1+ is bonded in a distorted L-shaped geometry to two equivalent N3- atoms. Both K–N bond lengths are 3.04 Å. Al3+ is bonded in a tetrahedral geometry to two equivalent N3- and two equivalent H1+ atoms. Both Al–N bond lengths are 1.98 Å. Both Al–H bond lengths are 1.61 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a 3-coordinate geometry to one K1+, one Al3+, and one N3- atom. The N–N bond length is 1.18 Å. In the second N3- site, N3- is bonded in a distorted single-bond geometry to one N3- atom. H1+ is bonded in a single-bond geometry to one Al3+ atom.