CeCu2Al4Si crystallizes in the orthorhombic Pmm2 space group. Ce(1) is bonded in a 16-coordinate geometry to four equivalent Cu(2), two equivalent Al(1), two equivalent Al(2), two equivalent Al(3), four equivalent Al(4), and two equivalent Si(1) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted body-centered cubic geometry to two equivalent Al(1), two equivalent Al(2), two equivalent Al(3), and two equivalent Si(1) atoms. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to four equivalent Ce(1), one Al(4), two equivalent Al(2), and two equivalent Al(3) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Ce(1), two equivalent Cu(1), two equivalent Al(4), and four equivalent Si(1) atoms. In the second Al site, Al(2) is bonded in a 5-coordinate geometry to two equivalent Ce(1), two equivalent Cu(1), two equivalent Cu(2), and one Si(1) atom. In the third Al site, Al(3) is bonded to two equivalent Ce(1), two equivalent Cu(1), and two equivalent Cu(2) atoms to form a mixture of distorted corner and edge-sharing AlCe2Cu4 tetrahedra. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to four equivalent Ce(1), one Cu(2), two equivalent Al(1), and two equivalent Si(1) atoms. Si(1) is bonded in a 11-coordinate geometry to two equivalent Ce(1), two equivalent Cu(1), one Al(2), two equivalent Al(4), and four equivalent Al(1) atoms.
CeCu2Al4Si crystallizes in the orthorhombic Pmm2 space group. Ce(1) is bonded in a 16-coordinate geometry to four equivalent Cu(2), two equivalent Al(1), two equivalent Al(2), two equivalent Al(3), four equivalent Al(4), and two equivalent Si(1) atoms. All Ce(1)-Cu(2) bond lengths are 3.24 Å. Both Ce(1)-Al(1) bond lengths are 3.36 Å. Both Ce(1)-Al(2) bond lengths are 3.30 Å. Both Ce(1)-Al(3) bond lengths are 3.28 Å. All Ce(1)-Al(4) bond lengths are 3.18 Å. Both Ce(1)-Si(1) bond lengths are 3.33 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted body-centered cubic geometry to two equivalent Al(1), two equivalent Al(2), two equivalent Al(3), and two equivalent Si(1) atoms. Both Cu(1)-Al(1) bond lengths are 2.46 Å. Both Cu(1)-Al(2) bond lengths are 2.55 Å. Both Cu(1)-Al(3) bond lengths are 2.57 Å. Both Cu(1)-Si(1) bond lengths are 2.48 Å. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to four equivalent Ce(1), one Al(4), two equivalent Al(2), and two equivalent Al(3) atoms. The Cu(2)-Al(4) bond length is 2.33 Å. Both Cu(2)-Al(2) bond lengths are 2.47 Å. Both Cu(2)-Al(3) bond lengths are 2.46 Å. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Ce(1), two equivalent Cu(1), two equivalent Al(4), and four equivalent Si(1) atoms. Both Al(1)-Al(4) bond lengths are 2.61 Å. All Al(1)-Si(1) bond lengths are 2.99 Å. In the second Al site, Al(2) is bonded in a 5-coordinate geometry to two equivalent Ce(1), two equivalent Cu(1), two equivalent Cu(2), and one Si(1) atom. The Al(2)-Si(1) bond length is 2.72 Å. In the third Al site, Al(3) is bonded to two equivalent Ce(1), two equivalent Cu(1), and two equivalent Cu(2) atoms to form a mixture of distorted corner and edge-sharing AlCe2Cu4 tetrahedra. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to four equivalent Ce(1), one Cu(2), two equivalent Al(1), and two equivalent Si(1) atoms. Both Al(4)-Si(1) bond lengths are 2.59 Å. Si(1) is bonded in a 11-coordinate geometry to two equivalent Ce(1), two equivalent Cu(1), one Al(2), two equivalent Al(4), and four equivalent Al(1) atoms.