CePtSi2 crystallizes in the orthorhombic Cmcm space group. Ce(1) is bonded in a 14-coordinate geometry to four equivalent Pt(1), four equivalent Si(2), and six equivalent Si(1) atoms. Pt(1) is bonded in a 5-coordinate geometry to four equivalent Ce(1), one Si(1), and four equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted single-bond geometry to six equivalent Ce(1), one Pt(1), and two equivalent Si(1) atoms. In the second Si site, Si(2) is bonded in a 4-coordinate geometry to four equivalent Ce(1) and four equivalent Pt(1) atoms.
CePtSi2 crystallizes in the orthorhombic Cmcm space group. Ce(1) is bonded in a 14-coordinate geometry to four equivalent Pt(1), four equivalent Si(2), and six equivalent Si(1) atoms. All Ce(1)-Pt(1) bond lengths are 3.26 Å. There are two shorter (3.22 Å) and two longer (3.27 Å) Ce(1)-Si(2) bond lengths. There are two shorter (3.17 Å) and four longer (3.21 Å) Ce(1)-Si(1) bond lengths. Pt(1) is bonded in a 5-coordinate geometry to four equivalent Ce(1), one Si(1), and four equivalent Si(2) atoms. The Pt(1)-Si(1) bond length is 2.41 Å. There are two shorter (2.43 Å) and two longer (2.44 Å) Pt(1)-Si(2) bond lengths. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted single-bond geometry to six equivalent Ce(1), one Pt(1), and two equivalent Si(1) atoms. Both Si(1)-Si(1) bond lengths are 2.42 Å. In the second Si site, Si(2) is bonded in a 4-coordinate geometry to four equivalent Ce(1) and four equivalent Pt(1) atoms.