MgCu3AsS4 crystallizes in the tetragonal P-42m space group. Mg(1) is bonded in a 10-coordinate geometry to four equivalent Cu(1), two equivalent As(1), and four equivalent S(1) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1) and four equivalent S(1) atoms. In the second Cu site, Cu(2) is bonded in a tetrahedral geometry to four equivalent S(1) atoms. As(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1) and four equivalent S(1) atoms. S(1) is bonded in a 5-coordinate geometry to one Mg(1), one Cu(2), two equivalent Cu(1), and one As(1) atom.
MgCu3AsS4 crystallizes in the tetragonal P-42m space group. Mg(1) is bonded in a 10-coordinate geometry to four equivalent Cu(1), two equivalent As(1), and four equivalent S(1) atoms. All Mg(1)-Cu(1) bond lengths are 2.71 Å. Both Mg(1)-As(1) bond lengths are 2.93 Å. All Mg(1)-S(1) bond lengths are 2.46 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1) and four equivalent S(1) atoms. All Cu(1)-S(1) bond lengths are 2.37 Å. In the second Cu site, Cu(2) is bonded in a tetrahedral geometry to four equivalent S(1) atoms. All Cu(2)-S(1) bond lengths are 2.37 Å. As(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1) and four equivalent S(1) atoms. All As(1)-S(1) bond lengths are 2.56 Å. S(1) is bonded in a 5-coordinate geometry to one Mg(1), one Cu(2), two equivalent Cu(1), and one As(1) atom.