CaAs3 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 8-coordinate geometry to one As(1), three equivalent As(3), and four equivalent As(2) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded to one Ca(1), one As(1), one As(2), and one As(3) atom to form distorted AsCaAs3 tetrahedra that share corners with six equivalent As(2)Ca4As2 pentagonal pyramids and corners with five equivalent As(3)Ca3As2 trigonal bipyramids. In the second As site, As(2) is bonded to four equivalent Ca(1), one As(1), and one As(2) atom to form distorted AsCa4As2 pentagonal pyramids that share corners with four equivalent As(2)Ca4As2 pentagonal pyramids, corners with six equivalent As(1)CaAs3 tetrahedra, corners with seven equivalent As(3)Ca3As2 trigonal bipyramids, edges with four equivalent As(2)Ca4As2 pentagonal pyramids, and edges with three equivalent As(3)Ca3As2 trigonal bipyramids. In the third As site, As(3) is bonded to three equivalent Ca(1), one As(1), and one As(3) atom to form distorted AsCa3As2 trigonal bipyramids that share corners with seven equivalent As(2)Ca4As2 pentagonal pyramids, corners with five equivalent As(1)CaAs3 tetrahedra, corners with two equivalent As(3)Ca3As2 trigonal bipyramids, edges with three equivalent As(2)Ca4As2 pentagonal pyramids, and edges with two equivalent As(3)Ca3As2 trigonal bipyramids.
CaAs3 crystallizes in the triclinic P-1 space group. Ca(1) is bonded in a 8-coordinate geometry to one As(1), three equivalent As(3), and four equivalent As(2) atoms. The Ca(1)-As(1) bond length is 3.13 Å. There are a spread of Ca(1)-As(3) bond distances ranging from 3.03-3.19 Å. There are a spread of Ca(1)-As(2) bond distances ranging from 3.02-3.35 Å. There are three inequivalent As sites. In the first As site, As(1) is bonded to one Ca(1), one As(1), one As(2), and one As(3) atom to form distorted AsCaAs3 tetrahedra that share corners with six equivalent As(2)Ca4As2 pentagonal pyramids and corners with five equivalent As(3)Ca3As2 trigonal bipyramids. The As(1)-As(1) bond length is 2.47 Å. The As(1)-As(2) bond length is 2.45 Å. The As(1)-As(3) bond length is 2.43 Å. In the second As site, As(2) is bonded to four equivalent Ca(1), one As(1), and one As(2) atom to form distorted AsCa4As2 pentagonal pyramids that share corners with four equivalent As(2)Ca4As2 pentagonal pyramids, corners with six equivalent As(1)CaAs3 tetrahedra, corners with seven equivalent As(3)Ca3As2 trigonal bipyramids, edges with four equivalent As(2)Ca4As2 pentagonal pyramids, and edges with three equivalent As(3)Ca3As2 trigonal bipyramids. The As(2)-As(2) bond length is 2.46 Å. In the third As site, As(3) is bonded to three equivalent Ca(1), one As(1), and one As(3) atom to form distorted AsCa3As2 trigonal bipyramids that share corners with seven equivalent As(2)Ca4As2 pentagonal pyramids, corners with five equivalent As(1)CaAs3 tetrahedra, corners with two equivalent As(3)Ca3As2 trigonal bipyramids, edges with three equivalent As(2)Ca4As2 pentagonal pyramids, and edges with two equivalent As(3)Ca3As2 trigonal bipyramids. The As(3)-As(3) bond length is 2.47 Å.