Ga2(Hg4Te5)3 crystallizes in the monoclinic Cm space group. There are eight inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to one Te(1), one Te(8), and two equivalent Te(3) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(2)Te4 tetrahedra, corners with two equivalent Hg(5)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, and corners with six equivalent Hg(3)Te4 tetrahedra. In the second Hg site, Hg(2) is bonded to one Te(1), one Te(2), and two equivalent Te(5) atoms to form corner-sharing HgTe4 tetrahedra. In the third Hg site, Hg(3) is bonded to one Te(1), one Te(10), and two equivalent Te(3) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(2)Te4 tetrahedra, corners with two equivalent Hg(5)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, corners with three equivalent Hg(1)Te4 tetrahedra, and corners with three equivalent Hg(3)Te4 tetrahedra. In the fourth Hg site, Hg(4) is bonded to one Te(2), one Te(4), and two equivalent Te(7) atoms to form corner-sharing HgTe4 tetrahedra. In the fifth Hg site, Hg(5) is bonded to one Te(2), one Te(3), and two equivalent Te(5) atoms to form corner-sharing HgTe4 tetrahedra. In the sixth Hg site, Hg(6) is bonded to one Te(4), one Te(6), and two equivalent Te(9) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(4)Te4 tetrahedra, corners with two equivalent Hg(7)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, and corners with six equivalent Hg(8)Te4 tetrahedra. In the seventh Hg site, Hg(7) is bonded to one Te(4), one Te(5), and two equivalent Te(7) atoms to form corner-sharing HgTe4 tetrahedra. In the eighth Hg site, Hg(8) is bonded to one Te(6), one Te(7), and two equivalent Te(9) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(4)Te4 tetrahedra, corners with two equivalent Hg(7)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, corners with three equivalent Hg(6)Te4 tetrahedra, and corners with three equivalent Hg(8)Te4 tetrahedra. Ga(1) is bonded to one Te(8), one Te(9), and two equivalent Te(10) atoms to form GaTe4 tetrahedra that share  a cornercorner with one Hg(1)Te4 tetrahedra,  a cornercorner with one Hg(6)Te4 tetrahedra, corners with two equivalent Hg(3)Te4 tetrahedra, corners with two equivalent Hg(8)Te4 tetrahedra, and corners with three equivalent Ga(1)Te4 tetrahedra. There are ten inequivalent Te sites. In the first Te site, Te(1) is bonded to one Hg(1), one Hg(2), and two equivalent Hg(3) atoms to form corner-sharing TeHg4 tetrahedra. In the second Te site, Te(2) is bonded to one Hg(2), one Hg(4), and two equivalent Hg(5) atoms to form corner-sharing TeHg4 tetrahedra. In the third Te site, Te(3) is bonded to one Hg(1), one Hg(5), and two equivalent Hg(3) atoms to form corner-sharing TeHg4 tetrahedra. In the fourth Te site, Te(4) is bonded to one Hg(4), one Hg(6), and two equivalent Hg(7) atoms to form TeHg4 tetrahedra that share  a cornercorner with one Te(2)Hg4 tetrahedra, corners with two equivalent Te(9)GaHg3 tetrahedra, corners with two equivalent Te(5)Hg4 tetrahedra, and corners with six equivalent Te(7)Hg4 tetrahedra. In the fifth Te site, Te(5) is bonded to one Hg(2), one Hg(7), and two equivalent Hg(5) atoms to form corner-sharing TeHg4 tetrahedra. In the sixth Te site, Te(6) is bonded in a trigonal non-coplanar geometry to one Hg(6) and two equivalent Hg(8) atoms. In the seventh Te site, Te(7) is bonded to one Hg(4), one Hg(8), and two equivalent Hg(7) atoms to form TeHg4 tetrahedra that share  a cornercorner with one Te(2)Hg4 tetrahedra, corners with two equivalent Te(9)GaHg3 tetrahedra, corners with two equivalent Te(5)Hg4 tetrahedra, corners with three equivalent Te(4)Hg4 tetrahedra, and corners with three equivalent Te(7)Hg4 tetrahedra. In the eighth Te site, Te(8) is bonded in a trigonal non-coplanar geometry to one Hg(1) and two equivalent Ga(1) atoms. In the ninth Te site, Te(9) is bonded to one Hg(6), two equivalent Hg(8), and one Ga(1) atom to form TeGaHg3 tetrahedra that share  a cornercorner with one Te(4)Hg4 tetrahedra, corners with two equivalent Te(7)Hg4 tetrahedra, and corners with three equivalent Te(9)GaHg3 tetrahedra. In the tenth Te site, Te(10) is bonded in a trigonal non-coplanar geometry to one Hg(3) and two equivalent Ga(1) atoms.
Ga2(Hg4Te5)3 crystallizes in the monoclinic Cm space group. There are eight inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to one Te(1), one Te(8), and two equivalent Te(3) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(2)Te4 tetrahedra, corners with two equivalent Hg(5)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, and corners with six equivalent Hg(3)Te4 tetrahedra. The Hg(1)-Te(1) bond length is 2.85 Å. The Hg(1)-Te(8) bond length is 2.89 Å. Both Hg(1)-Te(3) bond lengths are 2.87 Å. In the second Hg site, Hg(2) is bonded to one Te(1), one Te(2), and two equivalent Te(5) atoms to form corner-sharing HgTe4 tetrahedra. The Hg(2)-Te(1) bond length is 2.88 Å. The Hg(2)-Te(2) bond length is 2.86 Å. Both Hg(2)-Te(5) bond lengths are 2.87 Å. In the third Hg site, Hg(3) is bonded to one Te(1), one Te(10), and two equivalent Te(3) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(2)Te4 tetrahedra, corners with two equivalent Hg(5)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, corners with three equivalent Hg(1)Te4 tetrahedra, and corners with three equivalent Hg(3)Te4 tetrahedra. The Hg(3)-Te(1) bond length is 2.87 Å. The Hg(3)-Te(10) bond length is 2.89 Å. There is one shorter (2.85 Å) and one longer (2.87 Å) Hg(3)-Te(3) bond length. In the fourth Hg site, Hg(4) is bonded to one Te(2), one Te(4), and two equivalent Te(7) atoms to form corner-sharing HgTe4 tetrahedra. The Hg(4)-Te(2) bond length is 2.88 Å. The Hg(4)-Te(4) bond length is 2.88 Å. Both Hg(4)-Te(7) bond lengths are 2.86 Å. In the fifth Hg site, Hg(5) is bonded to one Te(2), one Te(3), and two equivalent Te(5) atoms to form corner-sharing HgTe4 tetrahedra. The Hg(5)-Te(2) bond length is 2.86 Å. The Hg(5)-Te(3) bond length is 2.88 Å. Both Hg(5)-Te(5) bond lengths are 2.86 Å. In the sixth Hg site, Hg(6) is bonded to one Te(4), one Te(6), and two equivalent Te(9) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(4)Te4 tetrahedra, corners with two equivalent Hg(7)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, and corners with six equivalent Hg(8)Te4 tetrahedra. The Hg(6)-Te(4) bond length is 2.89 Å. The Hg(6)-Te(6) bond length is 2.79 Å. Both Hg(6)-Te(9) bond lengths are 2.93 Å. In the seventh Hg site, Hg(7) is bonded to one Te(4), one Te(5), and two equivalent Te(7) atoms to form corner-sharing HgTe4 tetrahedra. The Hg(7)-Te(4) bond length is 2.86 Å. The Hg(7)-Te(5) bond length is 2.89 Å. There is one shorter (2.86 Å) and one longer (2.88 Å) Hg(7)-Te(7) bond length. In the eighth Hg site, Hg(8) is bonded to one Te(6), one Te(7), and two equivalent Te(9) atoms to form HgTe4 tetrahedra that share  a cornercorner with one Hg(4)Te4 tetrahedra, corners with two equivalent Hg(7)Te4 tetrahedra, corners with two equivalent Ga(1)Te4 tetrahedra, corners with three equivalent Hg(6)Te4 tetrahedra, and corners with three equivalent Hg(8)Te4 tetrahedra. The Hg(8)-Te(6) bond length is 2.79 Å. The Hg(8)-Te(7) bond length is 2.89 Å. Both Hg(8)-Te(9) bond lengths are 2.93 Å. Ga(1) is bonded to one Te(8), one Te(9), and two equivalent Te(10) atoms to form GaTe4 tetrahedra that share  a cornercorner with one Hg(1)Te4 tetrahedra,  a cornercorner with one Hg(6)Te4 tetrahedra, corners with two equivalent Hg(3)Te4 tetrahedra, corners with two equivalent Hg(8)Te4 tetrahedra, and corners with three equivalent Ga(1)Te4 tetrahedra. The Ga(1)-Te(8) bond length is 2.71 Å. The Ga(1)-Te(9) bond length is 2.68 Å. Both Ga(1)-Te(10) bond lengths are 2.71 Å. There are ten inequivalent Te sites. In the first Te site, Te(1) is bonded to one Hg(1), one Hg(2), and two equivalent Hg(3) atoms to form corner-sharing TeHg4 tetrahedra. In the second Te site, Te(2) is bonded to one Hg(2), one Hg(4), and two equivalent Hg(5) atoms to form corner-sharing TeHg4 tetrahedra. In the third Te site, Te(3) is bonded to one Hg(1), one Hg(5), and two equivalent Hg(3) atoms to form corner-sharing TeHg4 tetrahedra. In the fourth Te site, Te(4) is bonded to one Hg(4), one Hg(6), and two equivalent Hg(7) atoms to form TeHg4 tetrahedra that share  a cornercorner with one Te(2)Hg4 tetrahedra, corners with two equivalent Te(9)GaHg3 tetrahedra, corners with two equivalent Te(5)Hg4 tetrahedra, and corners with six equivalent Te(7)Hg4 tetrahedra. In the fifth Te site, Te(5) is bonded to one Hg(2), one Hg(7), and two equivalent Hg(5) atoms to form corner-sharing TeHg4 tetrahedra. In the sixth Te site, Te(6) is bonded in a trigonal non-coplanar geometry to one Hg(6) and two equivalent Hg(8) atoms. In the seventh Te site, Te(7) is bonded to one Hg(4), one Hg(8), and two equivalent Hg(7) atoms to form TeHg4 tetrahedra that share  a cornercorner with one Te(2)Hg4 tetrahedra, corners with two equivalent Te(9)GaHg3 tetrahedra, corners with two equivalent Te(5)Hg4 tetrahedra, corners with three equivalent Te(4)Hg4 tetrahedra, and corners with three equivalent Te(7)Hg4 tetrahedra. In the eighth Te site, Te(8) is bonded in a trigonal non-coplanar geometry to one Hg(1) and two equivalent Ga(1) atoms. In the ninth Te site, Te(9) is bonded to one Hg(6), two equivalent Hg(8), and one Ga(1) atom to form TeGaHg3 tetrahedra that share  a cornercorner with one Te(4)Hg4 tetrahedra, corners with two equivalent Te(7)Hg4 tetrahedra, and corners with three equivalent Te(9)GaHg3 tetrahedra. In the tenth Te site, Te(10) is bonded in a trigonal non-coplanar geometry to one Hg(3) and two equivalent Ga(1) atoms.