Ca3(InAs2)2 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent As(1) and four equivalent As(2) atoms to form distorted CaAs6 octahedra that share corners with two equivalent Ca(1)As6 octahedra, corners with five equivalent Ca(2)As6 octahedra, corners with six equivalent In(1)As4 tetrahedra, edges with six equivalent Ca(1)As6 octahedra, edges with three equivalent In(1)As4 tetrahedra, and  a faceface with one Ca(2)As6 octahedra. The corner-sharing octahedral tilt angles range from 13-55°. In the second Ca site, Ca(2) is bonded to two equivalent As(2) and four equivalent As(1) atoms to form distorted CaAs6 octahedra that share corners with ten equivalent Ca(1)As6 octahedra, corners with four equivalent In(1)As4 tetrahedra, edges with two equivalent Ca(2)As6 octahedra, edges with four equivalent In(1)As4 tetrahedra, and faces with two equivalent Ca(1)As6 octahedra. The corner-sharing octahedral tilt angles range from 32-55°. In(1) is bonded to two equivalent As(1) and two equivalent As(2) atoms to form distorted InAs4 tetrahedra that share corners with two equivalent Ca(2)As6 octahedra, corners with six equivalent Ca(1)As6 octahedra, corners with two equivalent In(1)As4 tetrahedra, edges with two equivalent Ca(2)As6 octahedra, edges with three equivalent Ca(1)As6 octahedra, and  an edgeedge with one In(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-68°. There are two inequivalent As sites. In the first As site, As(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent In(1) atoms to form distorted AsCa4In2 pentagonal pyramids that share corners with two equivalent As(2)Ca5In2 pentagonal bipyramids, corners with two equivalent As(1)Ca4In2 pentagonal pyramids, edges with seven equivalent As(2)Ca5In2 pentagonal bipyramids, and edges with four equivalent As(1)Ca4In2 pentagonal pyramids. In the second As site, As(2) is bonded to one Ca(2), four equivalent Ca(1), and two equivalent In(1) atoms to form distorted AsCa5In2 pentagonal bipyramids that share corners with three equivalent As(2)Ca5In2 pentagonal bipyramids, corners with two equivalent As(1)Ca4In2 pentagonal pyramids, edges with six equivalent As(2)Ca5In2 pentagonal bipyramids, and edges with seven equivalent As(1)Ca4In2 pentagonal pyramids.
Ca3(InAs2)2 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent As(1) and four equivalent As(2) atoms to form distorted CaAs6 octahedra that share corners with two equivalent Ca(1)As6 octahedra, corners with five equivalent Ca(2)As6 octahedra, corners with six equivalent In(1)As4 tetrahedra, edges with six equivalent Ca(1)As6 octahedra, edges with three equivalent In(1)As4 tetrahedra, and  a faceface with one Ca(2)As6 octahedra. The corner-sharing octahedral tilt angles range from 13-55°. Both Ca(1)-As(1) bond lengths are 2.97 Å. There are a spread of Ca(1)-As(2) bond distances ranging from 3.05-3.40 Å. In the second Ca site, Ca(2) is bonded to two equivalent As(2) and four equivalent As(1) atoms to form distorted CaAs6 octahedra that share corners with ten equivalent Ca(1)As6 octahedra, corners with four equivalent In(1)As4 tetrahedra, edges with two equivalent Ca(2)As6 octahedra, edges with four equivalent In(1)As4 tetrahedra, and faces with two equivalent Ca(1)As6 octahedra. The corner-sharing octahedral tilt angles range from 32-55°. Both Ca(2)-As(2) bond lengths are 3.18 Å. All Ca(2)-As(1) bond lengths are 2.94 Å. In(1) is bonded to two equivalent As(1) and two equivalent As(2) atoms to form distorted InAs4 tetrahedra that share corners with two equivalent Ca(2)As6 octahedra, corners with six equivalent Ca(1)As6 octahedra, corners with two equivalent In(1)As4 tetrahedra, edges with two equivalent Ca(2)As6 octahedra, edges with three equivalent Ca(1)As6 octahedra, and  an edgeedge with one In(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 22-68°. There is one shorter (2.65 Å) and one longer (2.68 Å) In(1)-As(1) bond length. Both In(1)-As(2) bond lengths are 2.70 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to two equivalent Ca(1), two equivalent Ca(2), and two equivalent In(1) atoms to form distorted AsCa4In2 pentagonal pyramids that share corners with two equivalent As(2)Ca5In2 pentagonal bipyramids, corners with two equivalent As(1)Ca4In2 pentagonal pyramids, edges with seven equivalent As(2)Ca5In2 pentagonal bipyramids, and edges with four equivalent As(1)Ca4In2 pentagonal pyramids. In the second As site, As(2) is bonded to one Ca(2), four equivalent Ca(1), and two equivalent In(1) atoms to form distorted AsCa5In2 pentagonal bipyramids that share corners with three equivalent As(2)Ca5In2 pentagonal bipyramids, corners with two equivalent As(1)Ca4In2 pentagonal pyramids, edges with six equivalent As(2)Ca5In2 pentagonal bipyramids, and edges with seven equivalent As(1)Ca4In2 pentagonal pyramids.