ZrReSi2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 12-coordinate geometry to one Re(2), three equivalent Re(1), one Si(4), one Si(5), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Zr site, Zr(2) is bonded in a 7-coordinate geometry to two equivalent Re(2), four equivalent Re(1), two equivalent Si(1), two equivalent Si(2), and three equivalent Si(4) atoms. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded to two equivalent Zr(2), three equivalent Zr(1), one Re(2), one Si(2), one Si(3), one Si(4), one Si(5), and two equivalent Si(1) atoms to form distorted ReZr5ReSi6 cuboctahedra that share corners with three equivalent Re(2)Zr4Re2Si6 cuboctahedra, corners with five equivalent Re(1)Zr5ReSi6 cuboctahedra,  an edgeedge with one Re(2)Zr4Re2Si6 cuboctahedra, edges with two equivalent Re(1)Zr5ReSi6 cuboctahedra, faces with two equivalent Re(2)Zr4Re2Si6 cuboctahedra, and faces with three equivalent Re(1)Zr5ReSi6 cuboctahedra. In the second Re site, Re(2) is bonded to two equivalent Zr(1), two equivalent Zr(2), two equivalent Re(1), two equivalent Si(1), two equivalent Si(4), and two equivalent Si(5) atoms to form ReZr4Re2Si6 cuboctahedra that share corners with six equivalent Re(1)Zr5ReSi6 cuboctahedra,  an edgeedge with one Re(2)Zr4Re2Si6 cuboctahedra, edges with two equivalent Re(1)Zr5ReSi6 cuboctahedra,  a faceface with one Re(2)Zr4Re2Si6 cuboctahedra, and faces with four equivalent Re(1)Zr5ReSi6 cuboctahedra. There are five inequivalent Si sites. In the first Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Zr(2), four equivalent Zr(1), two equivalent Re(1), and one Si(2) atom. In the second Si site, Si(3) is bonded in a 7-coordinate geometry to four equivalent Zr(1), two equivalent Re(1), and one Si(3) atom. In the third Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Zr(1), three equivalent Zr(2), two equivalent Re(1), and two equivalent Re(2) atoms. In the fourth Si site, Si(5) is bonded in a 6-coordinate geometry to two equivalent Zr(1), two equivalent Re(1), and two equivalent Re(2) atoms. In the fifth Si site, Si(1) is bonded in a 7-coordinate geometry to one Zr(2), two equivalent Zr(1), one Re(2), two equivalent Re(1), and one Si(1) atom.
ZrReSi2 crystallizes in the orthorhombic Pbam space group. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 12-coordinate geometry to one Re(2), three equivalent Re(1), one Si(4), one Si(5), two equivalent Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. The Zr(1)-Re(2) bond length is 3.09 Å. There are a spread of Zr(1)-Re(1) bond distances ranging from 3.03-3.12 Å. The Zr(1)-Si(4) bond length is 2.77 Å. The Zr(1)-Si(5) bond length is 2.81 Å. There is one shorter (2.87 Å) and one longer (2.88 Å) Zr(1)-Si(1) bond length. There is one shorter (2.88 Å) and one longer (2.91 Å) Zr(1)-Si(2) bond length. There is one shorter (2.86 Å) and one longer (2.96 Å) Zr(1)-Si(3) bond length. In the second Zr site, Zr(2) is bonded in a 7-coordinate geometry to two equivalent Re(2), four equivalent Re(1), two equivalent Si(1), two equivalent Si(2), and three equivalent Si(4) atoms. Both Zr(2)-Re(2) bond lengths are 3.12 Å. There are two shorter (3.12 Å) and two longer (3.21 Å) Zr(2)-Re(1) bond lengths. Both Zr(2)-Si(1) bond lengths are 2.87 Å. There is one shorter (2.79 Å) and one longer (2.85 Å) Zr(2)-Si(2) bond length. There are a spread of Zr(2)-Si(4) bond distances ranging from 2.85-2.92 Å. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded to two equivalent Zr(2), three equivalent Zr(1), one Re(2), one Si(2), one Si(3), one Si(4), one Si(5), and two equivalent Si(1) atoms to form distorted ReZr5ReSi6 cuboctahedra that share corners with three equivalent Re(2)Zr4Re2Si6 cuboctahedra, corners with five equivalent Re(1)Zr5ReSi6 cuboctahedra,  an edgeedge with one Re(2)Zr4Re2Si6 cuboctahedra, edges with two equivalent Re(1)Zr5ReSi6 cuboctahedra, faces with two equivalent Re(2)Zr4Re2Si6 cuboctahedra, and faces with three equivalent Re(1)Zr5ReSi6 cuboctahedra. The Re(1)-Re(2) bond length is 2.72 Å. The Re(1)-Si(2) bond length is 2.44 Å. The Re(1)-Si(3) bond length is 2.44 Å. The Re(1)-Si(4) bond length is 2.61 Å. The Re(1)-Si(5) bond length is 2.66 Å. There is one shorter (2.54 Å) and one longer (2.62 Å) Re(1)-Si(1) bond length. In the second Re site, Re(2) is bonded to two equivalent Zr(1), two equivalent Zr(2), two equivalent Re(1), two equivalent Si(1), two equivalent Si(4), and two equivalent Si(5) atoms to form ReZr4Re2Si6 cuboctahedra that share corners with six equivalent Re(1)Zr5ReSi6 cuboctahedra,  an edgeedge with one Re(2)Zr4Re2Si6 cuboctahedra, edges with two equivalent Re(1)Zr5ReSi6 cuboctahedra,  a faceface with one Re(2)Zr4Re2Si6 cuboctahedra, and faces with four equivalent Re(1)Zr5ReSi6 cuboctahedra. Both Re(2)-Si(1) bond lengths are 2.57 Å. Both Re(2)-Si(4) bond lengths are 2.54 Å. Both Re(2)-Si(5) bond lengths are 2.55 Å. There are five inequivalent Si sites. In the first Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Zr(2), four equivalent Zr(1), two equivalent Re(1), and one Si(2) atom. The Si(2)-Si(2) bond length is 2.44 Å. In the second Si site, Si(3) is bonded in a 7-coordinate geometry to four equivalent Zr(1), two equivalent Re(1), and one Si(3) atom. The Si(3)-Si(3) bond length is 2.46 Å. In the third Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Zr(1), three equivalent Zr(2), two equivalent Re(1), and two equivalent Re(2) atoms. In the fourth Si site, Si(5) is bonded in a 6-coordinate geometry to two equivalent Zr(1), two equivalent Re(1), and two equivalent Re(2) atoms. In the fifth Si site, Si(1) is bonded in a 7-coordinate geometry to one Zr(2), two equivalent Zr(1), one Re(2), two equivalent Re(1), and one Si(1) atom. The Si(1)-Si(1) bond length is 2.36 Å.