MgB3 crystallizes in the tetragonal P4/mmm space group. Mg(1) is bonded in a 13-coordinate geometry to one Mg(1), four equivalent B(2), and eight equivalent B(1) atoms. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Mg(1), two equivalent B(2), and three equivalent B(1) atoms. In the second B site, B(2) is bonded in a 4-coordinate geometry to four equivalent Mg(1) and four equivalent B(1) atoms.
MgB3 crystallizes in the tetragonal P4/mmm space group. Mg(1) is bonded in a 13-coordinate geometry to one Mg(1), four equivalent B(2), and eight equivalent B(1) atoms. The Mg(1)-Mg(1) bond length is 2.85 Å. All Mg(1)-B(2) bond lengths are 2.96 Å. All Mg(1)-B(1) bond lengths are 2.83 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to four equivalent Mg(1), two equivalent B(2), and three equivalent B(1) atoms. Both B(1)-B(2) bond lengths are 1.73 Å. There is one shorter (1.64 Å) and two longer (1.75 Å) B(1)-B(1) bond lengths. In the second B site, B(2) is bonded in a 4-coordinate geometry to four equivalent Mg(1) and four equivalent B(1) atoms.