Ni3GaAs crystallizes in the hexagonal P-6m2 space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 11-coordinate geometry to two equivalent Ni(1), three equivalent Ni(2), three equivalent Ga(1), and three equivalent As(1) atoms. In the second Ni site, Ni(2) is bonded to six equivalent Ni(1), three equivalent Ga(1), and two equivalent As(1) atoms to form a mixture of distorted face and corner-sharing NiGa3Ni6As2 trigonal bipyramids. Ga(1) is bonded in a 9-coordinate geometry to three equivalent Ni(2) and six equivalent Ni(1) atoms. As(1) is bonded in a 8-coordinate geometry to two equivalent Ni(2) and six equivalent Ni(1) atoms.
Ni3GaAs crystallizes in the hexagonal P-6m2 space group. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 11-coordinate geometry to two equivalent Ni(1), three equivalent Ni(2), three equivalent Ga(1), and three equivalent As(1) atoms. There is one shorter (2.39 Å) and one longer (2.49 Å) Ni(1)-Ni(1) bond length. All Ni(1)-Ni(2) bond lengths are 2.60 Å. All Ni(1)-Ga(1) bond lengths are 2.60 Å. All Ni(1)-As(1) bond lengths are 2.58 Å. In the second Ni site, Ni(2) is bonded to six equivalent Ni(1), three equivalent Ga(1), and two equivalent As(1) atoms to form a mixture of distorted face and corner-sharing NiGa3Ni6As2 trigonal bipyramids. All Ni(2)-Ga(1) bond lengths are 2.28 Å. Both Ni(2)-As(1) bond lengths are 2.44 Å. Ga(1) is bonded in a 9-coordinate geometry to three equivalent Ni(2) and six equivalent Ni(1) atoms. As(1) is bonded in a 8-coordinate geometry to two equivalent Ni(2) and six equivalent Ni(1) atoms.