CuSi4P3 is Clathrate-derived structured and crystallizes in the trigonal R3m space group. Cu(1) is bonded to one Si(4) and three equivalent P(3) atoms to form distorted CuSiP3 tetrahedra that share corners with three equivalent Si(3)P4 tetrahedra, corners with three equivalent Si(1)Si3P tetrahedra, and corners with six equivalent Cu(1)SiP3 tetrahedra. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent Si(4) and one P(1) atom to form distorted SiSi3P tetrahedra that share corners with three equivalent Cu(1)SiP3 tetrahedra, corners with three equivalent Si(2)P4 tetrahedra, and corners with six equivalent Si(1)Si3P tetrahedra. In the second Si site, Si(2) is bonded to one P(2) and three equivalent P(1) atoms to form SiP4 tetrahedra that share corners with three equivalent Si(3)P4 tetrahedra, corners with three equivalent Si(1)Si3P tetrahedra, and corners with six equivalent Si(2)P4 tetrahedra. In the third Si site, Si(3) is bonded to one P(3) and three equivalent P(2) atoms to form SiP4 tetrahedra that share corners with three equivalent Cu(1)SiP3 tetrahedra, corners with three equivalent Si(2)P4 tetrahedra, and corners with six equivalent Si(3)P4 tetrahedra. In the fourth Si site, Si(4) is bonded to one Cu(1) and three equivalent Si(1) atoms to form SiCuSi3 tetrahedra that share corners with three equivalent P(3)Cu3Si tetrahedra, corners with three equivalent P(1)Si4 tetrahedra, and corners with six equivalent Si(4)CuSi3 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one Si(1) and three equivalent Si(2) atoms to form PSi4 tetrahedra that share corners with three equivalent Si(4)CuSi3 tetrahedra, corners with three equivalent P(2)Si4 tetrahedra, and corners with six equivalent P(1)Si4 tetrahedra. In the second P site, P(2) is bonded to one Si(2) and three equivalent Si(3) atoms to form PSi4 tetrahedra that share corners with three equivalent P(3)Cu3Si tetrahedra, corners with three equivalent P(1)Si4 tetrahedra, and corners with six equivalent P(2)Si4 tetrahedra. In the third P site, P(3) is bonded to three equivalent Cu(1) and one Si(3) atom to form PCu3Si tetrahedra that share corners with three equivalent Si(4)CuSi3 tetrahedra, corners with three equivalent P(2)Si4 tetrahedra, and corners with six equivalent P(3)Cu3Si tetrahedra.
CuSi4P3 is Clathrate-derived structured and crystallizes in the trigonal R3m space group. Cu(1) is bonded to one Si(4) and three equivalent P(3) atoms to form distorted CuSiP3 tetrahedra that share corners with three equivalent Si(3)P4 tetrahedra, corners with three equivalent Si(1)Si3P tetrahedra, and corners with six equivalent Cu(1)SiP3 tetrahedra. The Cu(1)-Si(4) bond length is 2.38 Å. All Cu(1)-P(3) bond lengths are 2.29 Å. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent Si(4) and one P(1) atom to form distorted SiSi3P tetrahedra that share corners with three equivalent Cu(1)SiP3 tetrahedra, corners with three equivalent Si(2)P4 tetrahedra, and corners with six equivalent Si(1)Si3P tetrahedra. All Si(1)-Si(4) bond lengths are 2.35 Å. The Si(1)-P(1) bond length is 2.28 Å. In the second Si site, Si(2) is bonded to one P(2) and three equivalent P(1) atoms to form SiP4 tetrahedra that share corners with three equivalent Si(3)P4 tetrahedra, corners with three equivalent Si(1)Si3P tetrahedra, and corners with six equivalent Si(2)P4 tetrahedra. The Si(2)-P(2) bond length is 2.26 Å. All Si(2)-P(1) bond lengths are 2.29 Å. In the third Si site, Si(3) is bonded to one P(3) and three equivalent P(2) atoms to form SiP4 tetrahedra that share corners with three equivalent Cu(1)SiP3 tetrahedra, corners with three equivalent Si(2)P4 tetrahedra, and corners with six equivalent Si(3)P4 tetrahedra. The Si(3)-P(3) bond length is 2.21 Å. All Si(3)-P(2) bond lengths are 2.34 Å. In the fourth Si site, Si(4) is bonded to one Cu(1) and three equivalent Si(1) atoms to form SiCuSi3 tetrahedra that share corners with three equivalent P(3)Cu3Si tetrahedra, corners with three equivalent P(1)Si4 tetrahedra, and corners with six equivalent Si(4)CuSi3 tetrahedra. There are three inequivalent P sites. In the first P site, P(1) is bonded to one Si(1) and three equivalent Si(2) atoms to form PSi4 tetrahedra that share corners with three equivalent Si(4)CuSi3 tetrahedra, corners with three equivalent P(2)Si4 tetrahedra, and corners with six equivalent P(1)Si4 tetrahedra. In the second P site, P(2) is bonded to one Si(2) and three equivalent Si(3) atoms to form PSi4 tetrahedra that share corners with three equivalent P(3)Cu3Si tetrahedra, corners with three equivalent P(1)Si4 tetrahedra, and corners with six equivalent P(2)Si4 tetrahedra. In the third P site, P(3) is bonded to three equivalent Cu(1) and one Si(3) atom to form PCu3Si tetrahedra that share corners with three equivalent Si(4)CuSi3 tetrahedra, corners with three equivalent P(2)Si4 tetrahedra, and corners with six equivalent P(3)Cu3Si tetrahedra.