Materials Data on AlNi4As3 by Materials Project
Ni4As3Al crystallizes in the hexagonal P-6m2 space group. The structure is two-dimensional and consists of one aluminum molecule and one Ni4As3 sheet oriented in the (0, 0, 1) direction. In the Ni4As3 sheet, there are two inequivalent Ni+1.50+ sites. In the first Ni+1.50+ site, Ni+1.50+ is bonded in a distorted trigonal non-coplanar geometry to three equivalent As3- atoms. All Ni–As bond lengths are 2.40 Å. In the second Ni+1.50+ site, Ni+1.50+ is bonded to six As3- atoms to form a mixture of face, edge, and corner-sharing NiAs6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are three shorter (2.45 Å) and three longer (2.47 Å) Ni–As bond lengths. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 6-coordinate geometry to six equivalent Ni+1.50+ atoms. In the second As3- site, As3- is bonded in a 6-coordinate geometry to six Ni+1.50+ atoms.