MgAg4(AsS)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 3-coordinate geometry to one Ag(3), two equivalent As(1), two equivalent As(4), one S(3), and two equivalent S(2) atoms. There are four inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to two equivalent Ag(3), one As(2), one S(2), and two equivalent S(4) atoms to form distorted AgAg2AsS3 tetrahedra that share  a cornercorner with one S(1)Ag3As tetrahedra, corners with two equivalent S(4)Ag3As tetrahedra, and edges with two equivalent Ag(1)Ag2AsS3 tetrahedra. In the second Ag site, Ag(2) is bonded in a 4-coordinate geometry to one As(1), one S(1), and two equivalent S(3) atoms. In the third Ag site, Ag(3) is bonded in a 7-coordinate geometry to one Mg(1), two equivalent Ag(1), one As(4), one S(4), and two equivalent S(2) atoms. In the fourth Ag site, Ag(4) is bonded to one As(3), one S(3), and two equivalent S(1) atoms to form AgAsS3 tetrahedra that share  a cornercorner with one S(4)Ag3As tetrahedra and corners with two equivalent Ag(4)AsS3 tetrahedra. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1), one Ag(2), two equivalent As(4), and one S(2) atom. In the second As site, As(2) is bonded in a 4-coordinate geometry to one Ag(1), two equivalent As(3), and one S(1) atom. In the third As site, As(3) is bonded in a 4-coordinate geometry to one Ag(4), two equivalent As(2), and one S(4) atom. In the fourth As site, As(4) is bonded in a 6-coordinate geometry to two equivalent Mg(1), one Ag(3), two equivalent As(1), and one S(3) atom. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Ag(2), two equivalent Ag(4), and one As(2) atom to form SAg3As tetrahedra that share  a cornercorner with one Ag(1)Ag2AsS3 tetrahedra, corners with two equivalent S(1)Ag3As tetrahedra, and corners with four equivalent S(3)MgAg3As trigonal bipyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Ag(1), two equivalent Ag(3), and one As(1) atom. In the third S site, S(3) is bonded to one Mg(1), one Ag(4), two equivalent Ag(2), and one As(4) atom to form distorted SMgAg3As trigonal bipyramids that share corners with four equivalent S(1)Ag3As tetrahedra and corners with two equivalent S(3)MgAg3As trigonal bipyramids. In the fourth S site, S(4) is bonded to one Ag(3), two equivalent Ag(1), and one As(3) atom to form SAg3As tetrahedra that share  a cornercorner with one Ag(4)AsS3 tetrahedra, corners with two equivalent Ag(1)Ag2AsS3 tetrahedra, and corners with two equivalent S(4)Ag3As tetrahedra.
MgAg4(AsS)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 3-coordinate geometry to one Ag(3), two equivalent As(1), two equivalent As(4), one S(3), and two equivalent S(2) atoms. The Mg(1)-Ag(3) bond length is 2.98 Å. There is one shorter (2.93 Å) and one longer (2.96 Å) Mg(1)-As(1) bond length. There is one shorter (2.77 Å) and one longer (2.85 Å) Mg(1)-As(4) bond length. The Mg(1)-S(3) bond length is 2.46 Å. There is one shorter (2.57 Å) and one longer (2.59 Å) Mg(1)-S(2) bond length. There are four inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to two equivalent Ag(3), one As(2), one S(2), and two equivalent S(4) atoms to form distorted AgAg2AsS3 tetrahedra that share  a cornercorner with one S(1)Ag3As tetrahedra, corners with two equivalent S(4)Ag3As tetrahedra, and edges with two equivalent Ag(1)Ag2AsS3 tetrahedra. There is one shorter (3.03 Å) and one longer (3.20 Å) Ag(1)-Ag(3) bond length. The Ag(1)-As(2) bond length is 2.64 Å. The Ag(1)-S(2) bond length is 2.67 Å. There is one shorter (2.68 Å) and one longer (2.73 Å) Ag(1)-S(4) bond length. In the second Ag site, Ag(2) is bonded in a 4-coordinate geometry to one As(1), one S(1), and two equivalent S(3) atoms. The Ag(2)-As(1) bond length is 2.86 Å. The Ag(2)-S(1) bond length is 2.53 Å. Both Ag(2)-S(3) bond lengths are 2.65 Å. In the third Ag site, Ag(3) is bonded in a 7-coordinate geometry to one Mg(1), two equivalent Ag(1), one As(4), one S(4), and two equivalent S(2) atoms. The Ag(3)-As(4) bond length is 3.12 Å. The Ag(3)-S(4) bond length is 2.50 Å. There is one shorter (2.80 Å) and one longer (3.19 Å) Ag(3)-S(2) bond length. In the fourth Ag site, Ag(4) is bonded to one As(3), one S(3), and two equivalent S(1) atoms to form AgAsS3 tetrahedra that share  a cornercorner with one S(4)Ag3As tetrahedra and corners with two equivalent Ag(4)AsS3 tetrahedra. The Ag(4)-As(3) bond length is 2.60 Å. The Ag(4)-S(3) bond length is 2.82 Å. Both Ag(4)-S(1) bond lengths are 2.59 Å. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 6-coordinate geometry to two equivalent Mg(1), one Ag(2), two equivalent As(4), and one S(2) atom. There is one shorter (2.55 Å) and one longer (2.56 Å) As(1)-As(4) bond length. The As(1)-S(2) bond length is 2.39 Å. In the second As site, As(2) is bonded in a 4-coordinate geometry to one Ag(1), two equivalent As(3), and one S(1) atom. There is one shorter (2.56 Å) and one longer (2.57 Å) As(2)-As(3) bond length. The As(2)-S(1) bond length is 2.29 Å. In the third As site, As(3) is bonded in a 4-coordinate geometry to one Ag(4), two equivalent As(2), and one S(4) atom. The As(3)-S(4) bond length is 2.30 Å. In the fourth As site, As(4) is bonded in a 6-coordinate geometry to two equivalent Mg(1), one Ag(3), two equivalent As(1), and one S(3) atom. The As(4)-S(3) bond length is 2.38 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded to one Ag(2), two equivalent Ag(4), and one As(2) atom to form SAg3As tetrahedra that share  a cornercorner with one Ag(1)Ag2AsS3 tetrahedra, corners with two equivalent S(1)Ag3As tetrahedra, and corners with four equivalent S(3)MgAg3As trigonal bipyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to two equivalent Mg(1), one Ag(1), two equivalent Ag(3), and one As(1) atom. In the third S site, S(3) is bonded to one Mg(1), one Ag(4), two equivalent Ag(2), and one As(4) atom to form distorted SMgAg3As trigonal bipyramids that share corners with four equivalent S(1)Ag3As tetrahedra and corners with two equivalent S(3)MgAg3As trigonal bipyramids. In the fourth S site, S(4) is bonded to one Ag(3), two equivalent Ag(1), and one As(3) atom to form SAg3As tetrahedra that share  a cornercorner with one Ag(4)AsS3 tetrahedra, corners with two equivalent Ag(1)Ag2AsS3 tetrahedra, and corners with two equivalent S(4)Ag3As tetrahedra.