Mg2NiH4 crystallizes in the orthorhombic Imm2 space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent H(1) and four equivalent H(2) atoms. Ni(1) is bonded in a distorted trigonal pyramidal geometry to two equivalent H(1) and two equivalent H(2) atoms. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted see-saw-like geometry to three equivalent Mg(1) and one Ni(1) atom. In the second H site, H(2) is bonded to four equivalent Mg(1) and one Ni(1) atom to form a mixture of distorted edge, corner, and face-sharing HMg4Ni square pyramids.
Mg2NiH4 crystallizes in the orthorhombic Imm2 space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent H(1) and four equivalent H(2) atoms. There is one shorter (2.02 Å) and two longer (2.28 Å) Mg(1)-H(1) bond lengths. There are two shorter (2.22 Å) and two longer (2.29 Å) Mg(1)-H(2) bond lengths. Ni(1) is bonded in a distorted trigonal pyramidal geometry to two equivalent H(1) and two equivalent H(2) atoms. Both Ni(1)-H(1) bond lengths are 1.53 Å. Both Ni(1)-H(2) bond lengths are 1.55 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted see-saw-like geometry to three equivalent Mg(1) and one Ni(1) atom. In the second H site, H(2) is bonded to four equivalent Mg(1) and one Ni(1) atom to form a mixture of distorted edge, corner, and face-sharing HMg4Ni square pyramids.