CaPtAs is hexagonal omega structure-derived structured and crystallizes in the tetragonal I4_1md space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent Pt(3), four equivalent Pt(2), two equivalent As(1), and four equivalent As(2) atoms to form a mixture of edge and face-sharing CaAs6Pt6 cuboctahedra. In the second Ca site, Ca(2) is bonded to two equivalent Pt(2), four equivalent Pt(1), two equivalent As(3), and four equivalent As(1) atoms to form a mixture of edge and face-sharing CaAs6Pt6 cuboctahedra. In the third Ca site, Ca(3) is bonded to two equivalent Pt(1), four equivalent Pt(3), two equivalent As(2), and four equivalent As(3) atoms to form a mixture of edge and face-sharing CaAs6Pt6 cuboctahedra. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 9-coordinate geometry to two equivalent Ca(3), four equivalent Ca(2), one As(1), and two equivalent As(3) atoms. In the second Pt site, Pt(2) is bonded in a 9-coordinate geometry to two equivalent Ca(2), four equivalent Ca(1), one As(2), and two equivalent As(1) atoms. In the third Pt site, Pt(3) is bonded in a 9-coordinate geometry to two equivalent Ca(1), four equivalent Ca(3), one As(3), and two equivalent As(2) atoms. In the fourth Pt site, Pt(3) is bonded in a 9-coordinate geometry to two equivalent Ca(1), four equivalent Ca(3), one As(3), and two equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), four equivalent Ca(2), one Pt(1), and two equivalent Pt(2) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Ca(3), four equivalent Ca(1), one Pt(2), and two equivalent Pt(3) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Ca(2), four equivalent Ca(3), one Pt(3), and two equivalent Pt(1) atoms.
CaPtAs is hexagonal omega structure-derived structured and crystallizes in the tetragonal I4_1md space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent Pt(3), four equivalent Pt(2), two equivalent As(1), and four equivalent As(2) atoms to form a mixture of edge and face-sharing CaAs6Pt6 cuboctahedra. Both Ca(1)-Pt(3) bond lengths are 3.21 Å. All Ca(1)-Pt(2) bond lengths are 3.20 Å. Both Ca(1)-As(1) bond lengths are 3.23 Å. All Ca(1)-As(2) bond lengths are 3.20 Å. In the second Ca site, Ca(2) is bonded to two equivalent Pt(2), four equivalent Pt(1), two equivalent As(3), and four equivalent As(1) atoms to form a mixture of edge and face-sharing CaAs6Pt6 cuboctahedra. Both Ca(2)-Pt(2) bond lengths are 3.25 Å. All Ca(2)-Pt(1) bond lengths are 3.20 Å. Both Ca(2)-As(3) bond lengths are 3.23 Å. All Ca(2)-As(1) bond lengths are 3.21 Å. In the third Ca site, Ca(3) is bonded to two equivalent Pt(1), four equivalent Pt(3), two equivalent As(2), and four equivalent As(3) atoms to form a mixture of edge and face-sharing CaAs6Pt6 cuboctahedra. Both Ca(3)-Pt(1) bond lengths are 3.22 Å. All Ca(3)-Pt(3) bond lengths are 3.21 Å. Both Ca(3)-As(2) bond lengths are 3.23 Å. All Ca(3)-As(3) bond lengths are 3.20 Å. There are four inequivalent Pt sites. In the first Pt site, Pt(1) is bonded in a 9-coordinate geometry to two equivalent Ca(3), four equivalent Ca(2), one As(1), and two equivalent As(3) atoms. The Pt(1)-As(1) bond length is 2.44 Å. Both Pt(1)-As(3) bond lengths are 2.44 Å. In the second Pt site, Pt(2) is bonded in a 9-coordinate geometry to two equivalent Ca(2), four equivalent Ca(1), one As(2), and two equivalent As(1) atoms. The Pt(2)-As(2) bond length is 2.42 Å. Both Pt(2)-As(1) bond lengths are 2.44 Å. In the third Pt site, Pt(3) is bonded in a 9-coordinate geometry to two equivalent Ca(1), four equivalent Ca(3), one As(3), and two equivalent As(2) atoms. All Pt(3)-Ca(3) bond lengths are 3.21 Å. The Pt(3)-As(3) bond length is 2.44 Å. Both Pt(3)-As(2) bond lengths are 2.42 Å. In the fourth Pt site, Pt(3) is bonded in a 9-coordinate geometry to two equivalent Ca(1), four equivalent Ca(3), one As(3), and two equivalent As(2) atoms. Both Pt(3)-Ca(1) bond lengths are 3.21 Å. The Pt(3)-As(3) bond length is 2.44 Å. Both Pt(3)-As(2) bond lengths are 2.42 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded in a 9-coordinate geometry to two equivalent Ca(1), four equivalent Ca(2), one Pt(1), and two equivalent Pt(2) atoms. In the second As site, As(2) is bonded in a 9-coordinate geometry to two equivalent Ca(3), four equivalent Ca(1), one Pt(2), and two equivalent Pt(3) atoms. In the third As site, As(3) is bonded in a 9-coordinate geometry to two equivalent Ca(2), four equivalent Ca(3), one Pt(3), and two equivalent Pt(1) atoms.