Eu4Zn51 crystallizes in the trigonal R-3 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 24-coordinate geometry to three equivalent Zn(1), three equivalent Zn(2), three equivalent Zn(7), three equivalent Zn(8), six equivalent Zn(3), and six equivalent Zn(5) atoms. In the second Eu site, Eu(2) is bonded in a 24-coordinate geometry to three equivalent Zn(1), three equivalent Zn(2), three equivalent Zn(7), three equivalent Zn(8), six equivalent Zn(4), and six equivalent Zn(6) atoms. There are ten inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 11-coordinate geometry to one Eu(1), one Eu(2), one Zn(5), one Zn(8), two equivalent Zn(1), two equivalent Zn(7), and three equivalent Zn(3) atoms. In the second Zn site, Zn(2) is bonded in a 12-coordinate geometry to one Eu(1), one Eu(2), one Zn(6), one Zn(7), one Zn(9), two equivalent Zn(2), two equivalent Zn(8), and three equivalent Zn(4) atoms. In the third Zn site, Zn(3) is bonded in a 11-coordinate geometry to two equivalent Eu(1), one Zn(7), two equivalent Zn(3), three equivalent Zn(1), and three equivalent Zn(5) atoms. In the fourth Zn site, Zn(4) is bonded in a 12-coordinate geometry to two equivalent Eu(2), one Zn(8), one Zn(9), two equivalent Zn(4), three equivalent Zn(2), and three equivalent Zn(6) atoms. In the fifth Zn site, Zn(5) is bonded in a 12-coordinate geometry to two equivalent Eu(1), one Zn(1), one Zn(10), one Zn(8), two equivalent Zn(5), two equivalent Zn(7), and three equivalent Zn(3) atoms. In the sixth Zn site, Zn(6) is bonded in a 12-coordinate geometry to two equivalent Eu(2), one Zn(10), one Zn(2), one Zn(7), two equivalent Zn(6), two equivalent Zn(8), and three equivalent Zn(4) atoms. In the seventh Zn site, Zn(7) is bonded in a 12-coordinate geometry to one Eu(1), one Eu(2), one Zn(10), one Zn(2), one Zn(3), one Zn(6), two equivalent Zn(1), two equivalent Zn(5), and two equivalent Zn(8) atoms. In the eighth Zn site, Zn(8) is bonded in a 12-coordinate geometry to one Eu(1), one Eu(2), one Zn(1), one Zn(10), one Zn(4), one Zn(5), two equivalent Zn(2), two equivalent Zn(6), and two equivalent Zn(7) atoms. In the ninth Zn site, Zn(9) is bonded in a cuboctahedral geometry to six equivalent Zn(2) and six equivalent Zn(4) atoms. In the tenth Zn site, Zn(10) is bonded in a cuboctahedral geometry to three equivalent Zn(5), three equivalent Zn(6), three equivalent Zn(7), and three equivalent Zn(8) atoms.
Eu4Zn51 crystallizes in the trigonal R-3 space group. There are two inequivalent Eu sites. In the first Eu site, Eu(1) is bonded in a 24-coordinate geometry to three equivalent Zn(1), three equivalent Zn(2), three equivalent Zn(7), three equivalent Zn(8), six equivalent Zn(3), and six equivalent Zn(5) atoms. All Eu(1)-Zn(1) bond lengths are 3.56 Å. All Eu(1)-Zn(2) bond lengths are 3.50 Å. All Eu(1)-Zn(7) bond lengths are 3.53 Å. All Eu(1)-Zn(8) bond lengths are 3.51 Å. There are three shorter (3.54 Å) and three longer (3.56 Å) Eu(1)-Zn(3) bond lengths. There are three shorter (3.51 Å) and three longer (3.53 Å) Eu(1)-Zn(5) bond lengths. In the second Eu site, Eu(2) is bonded in a 24-coordinate geometry to three equivalent Zn(1), three equivalent Zn(2), three equivalent Zn(7), three equivalent Zn(8), six equivalent Zn(4), and six equivalent Zn(6) atoms. All Eu(2)-Zn(1) bond lengths are 3.51 Å. All Eu(2)-Zn(2) bond lengths are 3.52 Å. All Eu(2)-Zn(7) bond lengths are 3.50 Å. All Eu(2)-Zn(8) bond lengths are 3.52 Å. There are three shorter (3.52 Å) and three longer (3.54 Å) Eu(2)-Zn(4) bond lengths. All Eu(2)-Zn(6) bond lengths are 3.53 Å. There are ten inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 11-coordinate geometry to one Eu(1), one Eu(2), one Zn(5), one Zn(8), two equivalent Zn(1), two equivalent Zn(7), and three equivalent Zn(3) atoms. The Zn(1)-Zn(5) bond length is 2.70 Å. The Zn(1)-Zn(8) bond length is 2.57 Å. Both Zn(1)-Zn(1) bond lengths are 2.67 Å. There is one shorter (2.54 Å) and one longer (2.68 Å) Zn(1)-Zn(7) bond length. There are a spread of Zn(1)-Zn(3) bond distances ranging from 2.65-2.87 Å. In the second Zn site, Zn(2) is bonded in a 12-coordinate geometry to one Eu(1), one Eu(2), one Zn(6), one Zn(7), one Zn(9), two equivalent Zn(2), two equivalent Zn(8), and three equivalent Zn(4) atoms. The Zn(2)-Zn(6) bond length is 2.69 Å. The Zn(2)-Zn(7) bond length is 2.51 Å. The Zn(2)-Zn(9) bond length is 2.64 Å. Both Zn(2)-Zn(2) bond lengths are 2.74 Å. There is one shorter (2.51 Å) and one longer (2.69 Å) Zn(2)-Zn(8) bond length. There are a spread of Zn(2)-Zn(4) bond distances ranging from 2.72-2.95 Å. In the third Zn site, Zn(3) is bonded in a 11-coordinate geometry to two equivalent Eu(1), one Zn(7), two equivalent Zn(3), three equivalent Zn(1), and three equivalent Zn(5) atoms. The Zn(3)-Zn(7) bond length is 2.69 Å. Both Zn(3)-Zn(3) bond lengths are 2.67 Å. There are a spread of Zn(3)-Zn(5) bond distances ranging from 2.52-2.69 Å. In the fourth Zn site, Zn(4) is bonded in a 12-coordinate geometry to two equivalent Eu(2), one Zn(8), one Zn(9), two equivalent Zn(4), three equivalent Zn(2), and three equivalent Zn(6) atoms. The Zn(4)-Zn(8) bond length is 2.68 Å. The Zn(4)-Zn(9) bond length is 2.64 Å. Both Zn(4)-Zn(4) bond lengths are 2.74 Å. There are two shorter (2.52 Å) and one longer (2.68 Å) Zn(4)-Zn(6) bond length. In the fifth Zn site, Zn(5) is bonded in a 12-coordinate geometry to two equivalent Eu(1), one Zn(1), one Zn(10), one Zn(8), two equivalent Zn(5), two equivalent Zn(7), and three equivalent Zn(3) atoms. The Zn(5)-Zn(10) bond length is 2.63 Å. The Zn(5)-Zn(8) bond length is 2.72 Å. Both Zn(5)-Zn(5) bond lengths are 2.74 Å. There is one shorter (2.74 Å) and one longer (2.94 Å) Zn(5)-Zn(7) bond length. In the sixth Zn site, Zn(6) is bonded in a 12-coordinate geometry to two equivalent Eu(2), one Zn(10), one Zn(2), one Zn(7), two equivalent Zn(6), two equivalent Zn(8), and three equivalent Zn(4) atoms. The Zn(6)-Zn(10) bond length is 2.62 Å. The Zn(6)-Zn(7) bond length is 2.71 Å. Both Zn(6)-Zn(6) bond lengths are 2.73 Å. There is one shorter (2.73 Å) and one longer (2.93 Å) Zn(6)-Zn(8) bond length. In the seventh Zn site, Zn(7) is bonded in a 12-coordinate geometry to one Eu(1), one Eu(2), one Zn(10), one Zn(2), one Zn(3), one Zn(6), two equivalent Zn(1), two equivalent Zn(5), and two equivalent Zn(8) atoms. The Zn(7)-Zn(10) bond length is 2.64 Å. There is one shorter (2.73 Å) and one longer (2.74 Å) Zn(7)-Zn(8) bond length. In the eighth Zn site, Zn(8) is bonded in a 12-coordinate geometry to one Eu(1), one Eu(2), one Zn(1), one Zn(10), one Zn(4), one Zn(5), two equivalent Zn(2), two equivalent Zn(6), and two equivalent Zn(7) atoms. The Zn(8)-Zn(10) bond length is 2.64 Å. In the ninth Zn site, Zn(9) is bonded in a cuboctahedral geometry to six equivalent Zn(2) and six equivalent Zn(4) atoms. In the tenth Zn site, Zn(10) is bonded in a cuboctahedral geometry to three equivalent Zn(5), three equivalent Zn(6), three equivalent Zn(7), and three equivalent Zn(8) atoms.